Sae J826-2008

SURFACE J826 NOV2008
VEHICLE
Issued 1962-11
STANDARD Revised 2008-11
Superseding J826 MAR2008
Devices for Use in Defining and Measuring Vehicle Seating Accommodation
RATIONALE
The March 2008 revision incorporated an inspection procedure for checking calibration of the H-point machine (Appendix
C). It also added specifications for the mounting surface of the head restraint measuring device.
Other changes included:
- 10 year phase-out period for the HPM

- Revision of HPM weight specification from 167 to 169.6 lb to reflect current HPM build
- New ambient humidity specification
- Narrower range of ambient test temperatures
- Clarification of muslin cloth specification
- Extensive revision of short couple method and addition of long couple method to Appendix A
- Terminology consistent with SAE J1100
- Editorial clarifications
This revision adds a check for knee and ankle rotation efforts to Appendix C. It also corrects an error in the specification
for the H1 divot rearward to the vertical angle block surface. In addition, the length of the optional CAD shoe was changed
from 200 to 203 mm to align with the current shoe length. A few other minor editorial changes were made to the text and
to Figure A4.
SAE J4002 (HPM-II) and SAE J826 (HPM) shall co-exist for a transition period of at least 10 years, preferably no longer,
from the first publication date of SAE J4002 (August 2005). Following this transition period SAE J826 will be withdrawn.
During the transition period, it remains up to the vehicle designers to decide which HPM to use. Regulatory bodies and
other parties that need to know shall be informed regarding which HPM was used.
__________________________________________________________________________________________________________________________________________
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entirely voluntary, and its applicability and suitability for any particular use, including any patent infringement arising therefrom, is the sole responsibility of the user.
SAE reviews each technical report at least every five years at which time it may be reaffirmed, revised, or cancelled. SAE invites your written comments and suggestions.
Copyright 2008 SAE International
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SAE J826 Revised NOV2008 -2-
TABLE OF CONTENTS
1. SCOPE.......................................................................................................................................................... 3
1.1 Purpose......................................................................................................................................................... 4
2. REFERENCES.............................................................................................................................................. 4
2.1 Applicable Publications ................................................................................................................................. 4
2.1.1 SAE Publications........................................................................................................................................... 4
2.2 Related Publications ..................................................................................................................................... 4
2.2.1 SAE Publications........................................................................................................................................... 4
3. DEFINITIONS ............................................................................................................................................... 4
3.1 Accelerator Heel Point, AHP......................................................................................................................... 4
3.2 Ankle (Foot) Angle, A46................................................................................................................................ 4
3.3 Ball of Foot, BOF........................................................................................................................................... 4
3.4 Cushion Angle, A27 ...................................................................................................................................... 5
3.5 Floor Reference Point, FRP.......................................................................................................................... 5
3.6 H-Point .......................................................................................................................................................... 5
3.7 Heel of Shoe ................................................................................................................................................. 5
3.8 Hip Angle, A42 .............................................................................................................................................. 5
3.9 Knee Angle, A44 ........................................................................................................................................... 5
3.10 Seating Reference Point, SgRP.................................................................................................................... 5
3.11 Shoe Plane.................................................................................................................................................... 5
3.12 Thigh Centerline............................................................................................................................................ 5
3.13 Thigh (Cushion) Line..................................................................................................................................... 5
3.14 Torso (Back) Angle, A40............................................................................................................................... 5
3.15 Torso Line ..................................................................................................................................................... 5
4. H-POINT TEMPLATEDESCRIPTION, APPLICATION, AND POSITIONING PROCEDURE .................. 5

4.1 Description .................................................................................................................................................... 5
4.2 ApplicationAids in displaying the following:............................................................................................... 5
4.3 Positioning Procedure for physical template (Figure 1)................................................................................ 5
4.3.1 Torso positioning for any specified Seating Reference Point and torso angle............................................. 5
4.3.2 Front SeatDriver Position .......................................................................................................................... 6
4.3.3 Front SeatDriver Position .......................................................................................................................... 6
4.3.4 Second RowLeft Side Occupant Position ................................................................................................. 6
4.3.5 Third RowLeft Side Occupant PositionForward Facing......................................................................... 7
4.3.6 Third RowLeft Side Occupant PositionRearward Facing ...................................................................... 7
4.3.7 H-point template layout using data obtained during H-point machine installation........................................ 7
4.4 Positioning Procedure for CAD template (Figure 2) ..................................................................................... 7
4.4.1 Use of optional shoe bottom ......................................................................................................................... 7
4.4.2 Positioning for any specified Seating Reference Point and torso angle....................................................... 7
4.4.3 Positioning for an unknown Seating Reference Point and torso angle. ....................................................... 8
5. H-POINT MACHINEDESCRIPTION, APPLICATION, AND INSTALLATION PROCEDURE................... 8

5.1 Description .................................................................................................................................................... 8
5.2 Application................................................................................................................................................... 10
5.3 Installation Procedure ................................................................................................................................. 10
6. SHORT-COUPLED SEATING CONDITION............................................................................................... 13
7. LONG-COUPLED SEATING CONDITION ................................................................................................. 13
8. DETERMINATION OF CUSHION ANGLE ................................................................................................. 13
9. H-POINT MACHINE AND TEMPLATE FABRICATION.............................................................................. 13
10. CALIBRATION OF THE H-POINT MACHINE ............................................................................................ 13
11. NOTES........................................................................................................................................................ 14
11.1 Marginal Indicia ........................................................................................................................................... 14
APPENDIX A INSTALLATION PROCEDURE FOR SHORT- AND LONG-COUPLED SEATING ................................... 15

APPENDIX B DETERMINATION OF CUSHION ANGLE ................................................................................................. 19
APPENDIX C SAE J826 H-POINT MACHINE CALIBRATION INSPECTION .................................................................. 21
APPENDIX D HEAD RESTRAINT MEASURING DEVICE (HRMD) ................................................................................. 32
FIGURE 1 H-POINT TEMPLATE ................................................................................................................................... 6

FIGURE 2 CAD VERSION OF H-POINT TEMPLATE ................................................................................................... 8
FIGURE 3 H-POINT MACHINE...................................................................................................................................... 9
FIGURE 4 H-POINT MACHINE...................................................................................................................................... 9
FIGURE A1 OVERVIEW OF SHORT-COUPLE CONDITION METHOD A.................................................................. 15
FIGURE A2 OVERVIEW OF SHORT-COUPLE CONDITION METHOD B.................................................................. 16
FIGURE A3 OVERVIEW OF LONG-COUPLE CONDITION .......................................................................................... 17
FIGURE A4 DECISION TREE FOR COUPLE METHODS - 2-D TEMPLATE PLACEMENT FOR 2nd
TO Nth ROW................................................................................................................................................ 18
FIGURE B1 DISTRIBUTION OF WEIGHTS FOR CUSHION ANGLE MEASUREMENT.............................................. 20
FIGURE C1 MEASUREMENT COORDINATE SYSTEM FOR HPM PANS .................................................................. 22
FIGURE C2 HPM TORQUE ADJUSTMENT. SOME HPMS MAY DIFFER FROM THIS ILLUSTRATION. .................. 23
FIGURE C3 HPM CUSHION AND BACK PAN SETUP ................................................................................................. 24
FIGURE C4 HPM CUSHION AND BACK PAN MEASUREMENTS ............................................................................... 25
FIGURE C5 LEG AND SHOE SETUP ............................................................................................................................ 27
FIGURE C6 ANKLE AND KNEE JOINT EFFORT CHECK ............................................................................................ 27
FIGURE C7 HPM WEIGHTS .......................................................................................................................................... 28
TABLE 1 LEG SEGMENT LENGTH .......................................................................................................................... 10

TABLE C1 HPM DIMENSIONS AND TOLERANCES (ITEM NUMBERS IDENTIFY A MEASUREMENT
SHOWN IN FIGURES C1-C7) .................................................................................................................... 29
1. SCOPE
The devices of this SAE Standard provide the means by which passenger compartment dimensions can be obtained
using a deflected seat rather than a free seat contour as a reference for defining seating space. All definitions and
dimensions used in conjunction with this document are described in SAE J1100. These devices are intended only to
apply to the driver side or center occupant seating spaces and are not to be construed as instruments which measure or
indicate occupant capabilities or comfort. This document covers only one H-point machine installed on a seat during each
test. Certified H-point templates and machines can be purchased from:
SAE International
400 Commonwealth Drive
Warrendale, PA 15096-0001
Specific procedures are included in Appendix A for seat measurements in short- and long-coupled vehicles and in
Appendix B for measurement of the driver seat cushion angle. Specifications and a calibration inspection procedure for
the H-point machine are given in Appendix C. Additional considerations are necessary when a Head Restraint Measuring
Device (HRMD) is mounted to an H-point machine (Appendix D).
1.1 Purpose
This document specifies a two-dimensional H-point template and a three-dimensional H-Point Machine (HPM) for use in
defining and measuring accommodation in vehicle seats.
2. REFERENCES
2.1 Applicable Publications
The following publications form a part of this specification to the extent specified herein. The latest issue of SAE
publications shall apply.
2.1.1 SAE Publications
Available from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside
USA and Canada) or 724-776-4970 (outside USA), www.sae.org.
SAE J182 Motor Vehicle Fiducial Marks and Three-Dimensional Reference System
SAE J1100 Motor Vehicle Dimensions
2.2 Related Publications
The following publications are provided for information purposes and are not a required part of this document.
2.2.1 SAE Publications
Available from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside
USA and Canada) or 724-776-4970 (outside USA), www.sae.org.
SAE J1516 Accommodation Tool Reference Point
SAE J1517 Driver Selected Seat Position
SAE J2732 Motor Vehicle Seat Dimensions
SAE J4002 H-Point Machine (HPM-II) Specifications and Procedure for H-Point DeterminationAuditing Vehicle
Seats
SAE J4003 H-Point Machine (HPM-II)Procedure for H-Point DeterminationBenchmarking Vehicle Seats
SAE J4004 Positioning the H-Point Design ToolSeating Reference Point and Seat Track Length
S. P. Geoffrey, "A 2-D ManikinThe Inside Story", Paper 267A presented at SAE International Congress, Detroit,
January 1961
3. DEFINITIONS
The following terms are defined in SAE J1100. When appropriate, added explanation is provided.
3.1 Accelerator Heel Point, AHP
3.2 Ankle (Foot) Angle, A46
3.3 Ball of Foot, BOF
3.4 Cushion Angle, A27
See Appendix B. Cushion Angle is measured using the H-point machine with the lower legs removed and the torso
weights redistributed about the cushion pan.
3.5 Floor Reference Point, FRP
3.6 H-Point
The H-point is located on the centerline of the H-point machine midway between the H-point sight buttons on either side
of the machine.
3.7 Heel of Shoe
3.8 Hip Angle, A42
3.9 Knee Angle, A44
3.10 Seating Reference Point, SgRP
3.11 Shoe Plane
3.12 Thigh Centerline
3.13 Thigh (Cushion) Line
3.14 Torso (Back) Angle, A401
3.15 Torso Line
4. H-POINT TEMPLATEDESCRIPTION, APPLICATION, AND POSITIONING PROCEDURE
4.1 Description
The H-point template (Figure 1) is constructed to represent in profile an adult male wearing shoes and corresponds to the
profile of the deflected seating contour of the H-point machine. Individual torso, thigh, lower leg, and shoe segments are
provided with locking pivot joints which can be used to fix the angular relationships of the segments. A torso angle
reference bar is included to orient the templates torso in relation to the vertical.
4.2 ApplicationAids in displaying the following:
Passenger compartment space and seating attitude during conception, engineering, and development stages of any
new vehicle.
Passenger compartment space and seating attitude for comparison and reporting purposes.
Data obtained from checks made with the H-point machine. (See Section 5).
4.3 Positioning Procedure for physical template (Figure 1)
4.3.1 Torso positioning for any specified Seating Reference Point and torso angle.
4.3.1.1 Position the H-point of the H-point template on the Seating Reference Point (SgRP) location on the layout.
1
Prior to 2008 SAE standards generally used the term back angle to describe the A40 dimension of SAE J1100. New
or revised standards beginning in 2008 will use the term torso angle for this dimension.
FIGURE 1 - H-POINT TEMPLATE
4.3.1.2 Set the torso angle reference bar quadrant scribe line marked on the torso angle quadrant to the specified torso
angle. Lock this quadrant in place.
4.3.1.3 Position the vertical reference scribe lines on the torso angle reference bar parallel to the body grid lines on the
layout drawing.
4.3.2 Front SeatDriver Position
Leg and shoe positioning for any specified Accelerator Heel Point location.
4.3.2.1 Holding the torso portion of the template in position as outlined in 4.3.1.1 to 4.3.1.3, position the heel point of
the template at the specified heel point location. This point on the layout is located on top of the heel pad or the
depressed floor covering surface at the Y-plane centerline of the accelerator pedal.
4.3.2.2 Holding the heel point at the specified location, rotate the shoe forward until the bottom of the shoe contacts the
undepressed accelerator pedal without infringing upon the 87 degrees minimum ankle (foot) angle. Normally
the pedal contact point is at or below the shoe ball of foot.
4.3.2.3 The undepressed accelerator pedal (point of contact with the bottom of shoe or shoe plane) may be determined
by locating the heel point as described previously and presetting and locking the ankle angle to 87 degrees.
4.3.3 Front SeatDriver Position
Leg and shoe positioning for any specified undepressed accelerator pedal location.
4.3.3.1 Holding the torso portion of the template in position as outlined in 4.3.1.1 to 4.3.1.3, position the bottom of the
shoe on the specified undepressed accelerator pedal and the heel as far forward as allowable. However, the
ankle angle is never less than 87 degrees. Lock ankle angle quadrant.
4.3.4 Second RowLeft Side Occupant Position
Leg and shoe positioning with the front seat in its SgRP position.
4.3.4.1 Holding the torso portion of the template in position as outlined in 4.3.1.1 to 4.3.1.3, except with the template H-
point on the SgRP of the second row seat, place the bottom of the shoe (heel and ball) on the depressed floor
covering line. The shoe is to be placed on the Y-plane centerline of the occupant or up to 127 mm (5 in) on
either side of the Y-plane centerline on the floor pan section.
NOTE: Locating the shoe either side of the Y-plane centerline of the occupant position will make the shoe location
compatible to the shoe location in the existing H-point machine installation procedure.
4.3.4.2 Move the shoe forward along the depressed floor covering line to the nearest interference of the toe, instep,
lower leg, or knee with the front seat. The ankle angle is to be restricted to a maximum of 130 degrees.
4.3.5 Third RowLeft Side Occupant PositionForward Facing
4.3.5.1 Follow the procedure as outlined for the second row seat, left side occupant position except that the template is
positioned in the third seat compartment.
4.3.6 Third RowLeft Side Occupant PositionRearward Facing
4.3.6.1 Follow the same procedure as outlined for the third rowside occupant positionforward facing except that
the shoe is positioned in the footwell to the interference with the rear end or closure.
4.3.7 H-point template layout using data obtained during H-point machine installation.
4.3.7.1 Position the H-point pivot of the template at the measured H-point location on a layout drawing or grid system.
4.3.7.2 Follow the procedure as outlined in 4.3.1.1 to 4.3.1.3 using the measured torso angle instead of the design
torso angle.
4.3.7.3 Holding the torso portion of the template in position as outlined previously, move the upper leg segment to the
measured hip angle shown on the hip angle quadrant.
4.3.7.4 Lock this quadrant in place.
4.3.7.5 Position and lock the ankle (foot) angle quadrant to the measured ankle angle.
4.3.7.6 Allowing the knee angle to vary as necessary, position the ankle pivot center on an arc from the hip pivot center
equal to the measured effective leg room less 254 mm.
4.4 Positioning Procedure for CAD template (Figure 2)
4.4.1 Use of optional shoe bottom
4.4.1.1 The standard H-point template has a shoe with an arched bottom and a defined heel shape. The BOF point on
the shoe is 203 mm (8 in) from the heel of the shoe. SAE manikins defined in SAE J4002 (HPM-II) and SAE
J4004 (HPD) have a shoe with a flat shoe bottom from the shoe heel to the BOF. There is no heel pocket. As
an option to aid in transitioning to these devices, users are strongly encouraged to flatten the shoe bottom of
the CAD template, as shown in Figure 2.
4.4.2 Positioning for any specified Seating Reference Point and torso angle.
4.4.2.1 Position the H-point of the CAD template on the SgRP at the specified torso angle. Use values for SgRP and
torso angle that are either specified by the manufacturer or can be determined from SAE J4004 or SAE
J1516/SAE J1517.
4.4.2.2 For the driver position, lock the ankle angle at 87 degrees. The bottom of the shoe should be touching the
undepressed accelerator pedal. Alternatively, the heel of shoe may be placed at the manufacturer AHP with the
bottom of the shoe touching the pedal.
FIGURE 2 - CAD VERSION OF H-POINT TEMPLATE
4.4.2.3 For passenger positions the shoe should be positioned with the heel of shoe at the floor reference point (FRP)
and the bottom of shoe on the floor.
4.4.3 Positioning for an unknown Seating Reference Point and torso angle.
4.4.3.1 Install the 3-D H-point machine to determine the seat H-point travel path. See SAE J1100 and SAE J4003/SAE
J4004 for determining BOF, AHP, shoe plane angle, SgRP and torso angle.
4.4.3.2 Install the CAD template as described in 4.4.2.
5. H-POINT MACHINEDESCRIPTION, APPLICATION, AND INSTALLATION PROCEDURE
5.1 Description
The back and cushion pans of the 3-D H-point machine (Figures 3 and 4) are representations of adult male contours2.
Constructed of reinforced plastic and metal, these separate back and cushion pans simulate the human torso and thigh
and are mechanically hinged at the H-point. A graduated sliding probe is hinged from the H-point to measure the head
room in the compartment. A quadrant is fastened to the probe to measure the torso angle. An adjustable thigh bar,
attached to the cushion pan, establishes the thigh centerline and serves as a baseline for the hip angle quadrant. Lower
leg segments, also adjustable in length, are connected to the cushion pan assembly at the knee joining T-bar, which is a
lateral extension of the adjustable thigh bar. Quadrants are incorporated in the lower leg segments to measure knee
angles. Shoe and ankle assemblies are calibrated to measure the angular relation to the lower leg segment. Positive
stops are provided in the thigh and lower leg segments for the 10th, 50th, and 95th percentile of adult male dimensions
(Table 1). Two spirit levels orient the device in space. Body segment weights are placed at the center of gravity locations
to provide seat penetration equivalent to a 77 kg (169.6 lb) male.3
The lower leg and thigh segments are available in 10th, 50th, and 95th percentile lengths. (See Table 1.)
2
The cushion and back pans of the HPM-II are an improved representation of adult male contours.
3
The adult male dimensions were in part taken from the 50th percentile data as acquired by Geoffrey. The remaining
dimensions were developed from U.S. Department of Health, Education, and Welfare data by the Design Devices
Subcommittee of the SAE Human Factors Engineering Committee, March, 1969.
FIGURE 3 - H-POINT MACHINE
FIGURE 4 - H-POINT MACHINE

SAE J826 Revised NOV2008 - 10 -
TABLE 1 - LEG SEGMENT LENGTH
10th 50th HPM 95th Template 95th

Percentile(1) Percentile(1) Percentile(2) Percentile(3)
mm (inches) mm (inches) mm (inches) mm
Lower leg segment (A) 392.7 (15.46) 417.1 (16.42) 458.7 (18.06) 459.1
Thigh segment (B) 407.7 (16.05) 431.5 (16.99) 455.7 (17.94) 456.0
1. S. P. Geoffrey, "A 2-D ManikinThe Inside Story." Paper 267A presented at SAE International Congress, Detroit, January 1961.
2. Values for the 95th percentile leg lengths were developed on the basis of best judgment of available data by the Design Devices
Subcommittee of the SAE Human Factors Engineering Committee at the July 1968 and March 1969 meetings.
3. Values for 95th percentile leg lengths of the template were established by comparisons of CMM scans of templates from several
manufacturers in 1992.
5.2 Application
5.2.1 Aid in the design and development of seats and seat materials.
5.2.2 Check vehicle seating compartments for conformance to design specifications, that is, relationship of H-point to
body structures, seats, controls, etc.
5.3 Installation Procedure
5.3.1 Dimensions are measured relative to the X and Z body zero planes by setting up the vehicle relative to the front
and rear fiducial mark (see SAE J182) height (H163 and H164). Curb and gross weight rating loads require
different fiducial mark heights. (See SAE J1100.) All interior dimensions are measured with the front seat in the
SgRP position as specified by the manufacturer. When the seatback has an angular adjustment separate from
the seat cushion, the normal driving or riding torso angle is specified by the manufacturer (A40). Use 25 degrees
if not specified. The cushion tilt adjustment, if available, should be in the design position.
5.3.2 Sufficient time (at least 4 h) shall be allowed to ensure that the seat material reaches room temperature. Room
temperature shall be 19 to 26 C (66 to 79 F). Room relative humidity should be within a range of 50% 5%. If
this relative humidity is not met, record both relative humidity and room temperature. If the seat to be checked has
never been sat upon, a 68 to 79 kg (150 to 175 lb) person shall sit on the seat twice for 1 min to flex the cushion
and back. All seat assemblies are to remain unloaded for a minimum period of 1/2 h (1 h preferred) prior to the
H-point machine installation.
5.3.3 Place a piece of muslin cotton cloth over the seat area to be checked. The muslin cloth should be of sufficient
size to prevent the machine from contacting the seat, approximately 910 mm square. The muslin should be a
plain cotton fabric having a thread count and weight typical of a durable, mid-grade, general-purpose muslin that
is available from most fabric stores. The muslin should be tucked in a sufficient amount to prevent hammocking
of the material. If the test is run in a buck, suitable floor covering sections, or equivalent, are to be placed under
the H-point machine's shoes.
5.3.4 Place cushion and back assembly of the H-point machine at the centerline of occupant (C/LO). C/LO is also the
centerline of H-point machine and is located in vehicle per manufacturer specifications. If specifications are not
available, locate C/LO as follows:
- for bucket front seats, seats with defined bolsters, or individual auxiliary seats, C/LO is the centerline of the seat.
- for bench (or other) seats, C/LO is located at the middle of the head restraint. If a head restraint is not fitted, locate
C/LO midway between the lap belt anchors. For the driver, C/LO may be aligned with the steering wheel center.
- 381 mm outboard from the vehicle centerline (as a last resort)
The C/LO should be moved inboard whenever the H-point machine is sitting far enough outboard that the seat edge will
not permit leveling of the H-point machine. It is moved inboard the necessary distance to permit leveling of the H-point
machine and the new dimension from centerline of vehicle to C/LO noted in recording measurements.
5.3.5 Use 95th percentile leg and thigh segments specified in Table 1.
5.3.6 Attach shoe and lower leg assemblies to the cushion pan assembly, either individually at the knee joint or by
using the T-bar lateral segment and lower leg assembly.
The T-bar lateral segment should be parallel to the ground and perpendicular to the Y-plane of the vehicle unless
otherwise specified by the manufacturer.
5.3.7 The shoe and leg positions of the H-point machine for the various individual seat positions to be checked are as
follows:
5.3.7.1 Front SeatDriver Position
The right shoe and leg assembly is placed on the undepressed (blocked or mechanically restrained) accelerator pedal
with the sole of the shoe on the pedal and the heel as far forward as allowable. The right leg is adjusted inboard on the T-
bar toward the centerline of the vehicle until just contacting the tunnel (or other components) or until the Ball of Foot on
the shoe is aligned with the center of the accelerator pedal pad unless specified otherwise by the manufacturer. Tunnel
contact at the heel is defined where the Heel Point on the shoe is at the beginning transition of horizontal to upturned
compressed carpet surface. The heel may not be placed on the toe board. However, the ankle angle is never less than
87 degrees. The 87 degree limit can be fixed by inserting the pin into the shoe assembly.
The left shoe is positioned on the floor or toe pan and located approximately the same distance to the left of the H-point
machine centerline as the right shoe is to the right. The T-bar should be maintained parallel to the ground.
5.3.7.2 Front SeatOccupant in Vehicle Centerline Position
The H-point machine is installed in the front seat vehicle centerline position with both legs extended at the specified
percentile, one on either side of the tunnel. The left shoe is placed on the undepressed accelerator pedal and the right
shoe is located to the right of the tunnel, approximately opposite and symmetrical in a manner that levels the knee joint T-
bar. A T-bar extension may be required to straddle the knee segments on either side of the tunnel. In vehicles having no
tunnel, the shoes are set approximately 254 mm (10 in) apart. The leg comfort angles are determined from the H-point
machine's left leg.
5.3.7.3 Second and Successive SeatsSide Occupant Position
The H-point machine is installed in the second seat outboard occupant position at the C/LO as described in 5.3.4. (Check
applicable seating arrangement drawing for specified location.) The two shoes are placed together, or up to 127 mm
(5 in) to either side of C/LO, and positioned to the nearest interference of the toe, instep, or lower leg with the front seat,
unless otherwise specified by the manufacturer. In instances where one shoe reaches interference before the other, the
one with the farthest interference will be used for dimensioning purposes. For additional H-point machine leg location
conditions and restrictions, see Appendix A. For a description of short- and long- coupled seating conditions, see Section
6 and Section 7.
5.3.7.4 Second and Successive SeatsOccupant in Vehicle Centerline Position
The H-point machine is installed in the second seat-vehicle centerline position with both the shoe and lower leg
assemblies on the normal floor, and placed astride the tunnel, if present. Both leg assemblies are extended to the
nearest interference of the toe, instep, or lower leg with the front seat.
If necessary, in order to clear lateral obstructions, such as seat belt anchors, tunnel width, etc., the T-bar may be
extended. In vehicles with no tunnel, set the H-point machine's shoes approximately 254 mm (10 in) apart.
5.3.8 Apply lower leg and thigh weights and level the H-point machine.
5.3.9 Tilt the back pan forward against the forward stop and draw the H-point machine away from the seatback using
the T-bar. Reposition the H-point machine on the seat by one of the following methods:
5.3.9.1 If the H-point machine tends to slide rearward, use the following procedure: Allow the H-point machine to slide
rearward until a forward horizontal restraining load on the T-bar is no longer required due to the cushion pan
contacting the seatback.
5.3.9.2 If the H-point machine does not tend to slide rearward, use the following procedure: Slide the H-point machine
rearward by a horizontal rearward load applied at the T-bar until the cushion pan contacts the seatback.
5.3.10 Apply a 10 kg (22 lb) load twice to the back and pan assembly positioned at the intersection of the hip angle
quadrant and the T-bar housing (Figure 3). The direction of load application should be maintained along a line
from the above intersection to a point just above the thigh bar housing. Then carefully return the back pan to the
seatback. Care must be exercised through the remainder of the procedure to prevent the H-point machine from
sliding forward.
5.3.11 Install the right and left buttock weights and then alternately the eight torso weights. Maintain H-point machine
level.
5.3.12 Tilt the back pan forward until the stop is contacted. Rock the H-point machine from side to side over a 10 degree
arc (5 degrees to each side of the vertical centerline) for three complete cycles to release any accumulated
friction between the H-point machine and the seat. During the rocking, the T-bar of the H-point machine may tend
to change from the specified horizontal and vertical alignment; therefore, the T-bar must be restrained and
properly aligned by applying an appropriate lateral load during the rocking motions. Care shall be exercised in
holding the T-bar and rocking the H-point machine to minimize inadvertent exterior loads applied in a vertical or
fore-and-aft direction. The H-point machine's shoes are not to be restrained or held during this step, and if the
shoes change position, they should be allowed to remain in that attitude at this time. Due to the movement of the
shoes during the H-point machine rocking operation, the shoes are repositioned as follows:
a. Front SeatAlternately lift each shoe off the floor the minimum necessary amount until no additional forward shoe
movement is obtained. During this lifting, the shoes are to be free to rotate and no forward or lateral loads are to be
applied. When each shoe is placed back in the down position, the heel is to be in contact with the floor and the ball
(sole) of the foot is to be in contact with the floor, toe board, or undepressed accelerator pedal.
b. Second and Successive SeatsAlternately move each shoe forward by applying a forward load to the heel of the
shoe, sliding the shoes forward until the shoe or leg interfere with the rear of the front seatback. This operation
releases any accumulated shoe friction and movement incurred during the lateral rocking step.
If the cushion pan is not level at the completion of this step, apply a sufficient lateral load to the top of the back pan to
level the H-point machine cushion pan on the seat.
5.3.13 Holding the T-bar to prevent the H-point machine from sliding forward on the seat cushion, proceed as follows:
a. Return the back pan to the seatback.
b. Apply a rearward force perpendicular to the torso angle bar just above the torso weights using the smaller of the
following forces:
1. Force sufficient to increase the hip angle by 3 degrees, or
2. 66 N (15 lb).
Alternately apply and release this force until the hip angle readout indicates that the back pan has reached a stable
position after the applied force has been released, that is, repeated identical hip angle readouts. Care shall be exercised
to minimize exterior downward or side forces applied to the H-point machine. If an H-point machine level adjustment is
necessary, rotate the back pan forward, re-level, and repeat the H-point machine back rocking.
5.3.14 If a rerun of the H-point machine installation is desired, the seat assembly should remain unloaded for a minimum
period of 1/2 h prior to the rerun. The loaded H-point machine should not be left on the assembly longer than the
time required to perform the test.
6. SHORT-COUPLED SEATING CONDITION
If the H-point couple distance is such that the H-point machine with 95th percentile leg lengths will not fit into a second or
successive row seat with the preceding row positioned at its SgRP location and attitude (that is, one or more components
of the assembled HPM interferes with the preceding row seat or structure), install the machine in accordance with the
method described in Appendix A.
7. LONG-COUPLED SEATING CONDITION
If the H-point couple distance, or seating package, is such that the H-point machine with 95th percentile leg lengths will
attain an ankle angle greater than 130 degrees with the preceding row positioned at its SgRP location and attitude (that
is, the foot to lower leg relationship is not limited by the preceding row seat component or other structure), install the
machine in accordance with the method described in Appendix A.
8. DETERMINATION OF CUSHION ANGLE
A measure called cushion angle has been developed to determine the attitude that a seat cushion imposes on the seated
occupant's thighs independent of seating package geometry. This measure uses the H-point machine with lower legs
removed and the torso weights redistributed about the seat pan.
Normally, the H-point machine thigh attitude depends on the seating package arrangement because the machine's shoe
location in the package sets the angle of the lower leg and thigh. Much like the torso angle reflects the torso attitude
imposed by the seat back on the three-dimensional H-point machine, cushion angle reflects the thigh attitude imposed by
the seat cushion. Neither torso angle nor cushion angle depend on the particular seating package geometry.
The cushion angle measurement procedure is presented in Appendix B.
9. H-POINT MACHINE AND TEMPLATE FABRICATION
Fabrication of the H-point machine and the H-point template must conform to design as specified in the SAE International
Standard SAE J826 specifications.
9.1 Each H-point machine must have a permanently attached identification plate showing the following information:
Three-Dimension H-Point Machine

No. ________________
This measuring device is constructed in full accordance with the SAE International Standard SAE J826 specifications.
9.2 Three H-point template leg segments are available duplicating 10th, 50th, and 95th percentile leg lengths of the
H-point machine.
10. CALIBRATION OF THE H-POINT MACHINE
A procedure for inspecting the HPM for calibration, together with specifications and tolerances for the various
measurements, is given in Appendix C. Beginning in 2008, calibrations of HPMs by an SAE sanctioned agency will
include a report on these measurements.
Two levels of calibration are envisioned:
1. Conventional use of the HPM for H-point determination
2. Use of the HPM in conjunction with a Head Restraint Measuring Device (HRMD) for the purpose of assessing head
restraint geometry (Appendix D)
A certification label on the HPM will indicate its level of calibration.
11. NOTES
11.1 Marginal Indicia
A change bar (l) located in the left margin is for the convenience of the user in locating areas where technical revisions,
not editorial changes, have been made to the previous issue of this document. An (R) symbol to the left of the document
title indicates a complete revision of the document, including technical revisions. Change bars and (R) are not used in
original publications, nor in documents that contain editorial changes only.
PREPARED BY THE SAE HUMAN ACCOMMODATION AND

DESIGN DEVICES STANDARDS COMMITTEE
APPENDIX A - INSTALLATION PROCEDURE FOR SHORT- AND LONG-COUPLED SEATING
A.1 A vehicle is said to be either short- or long-coupled if seating conditions exist as described in Sections 6 or 7,
respectively. For short-coupled seating, two distinct methods are employed for installing the HPM. Use Method
A if the HPM shoe can be placed on the floor between the seating rows without interfering with any vehicle
component. Use Method B if the HPM shoe cannot be placed on the floor between the seating rows. For
installation of the HPM in a long-coupled vehicle, see A.1.3.
A.1.1 Short-Coupled Seating - Method A (HPM shoe fits into available floor space)
a. Follow the installation procedure through 5.3.5.
b. Use one of the lower leg-shoe assemblies of the H-point machine and initially place the sole on the floor covering with
the heel as far rearward as possible.
c. Slide the lower leg and shoe forward on the floor until it is obstructed by the seat cushion or support structure and
mark a lateral line at the rear of the heel point.
d. Move the seat out of the way by using the available track travel, the forward tilt or seatback adjustment, or by physical
means.
e. Resume the general installation procedures except:
1. When positioning the shoes on the floor in 5.3.7.3, the rearmost point of the heels should be on the lateral line
determined in step c.
2. When completing the rocking motion in 5.3.12, care should be used to prevent jack-knifing of the legs, and
clam-shelling of the back and seat pans. The shoes are repositioned with the rearmost point of the heels on the
lateral line determined in step c.
f. L48, minimum knee clearance, is best determined graphically on the drawing, or mathematically in CAD by
transferring the physical HPM orientation to either environment, and following the SAE J1100 procedure.
g. L51, effective leg room, is determined by measuring the diagonal distance from the ankle pivot center to the H-point
plus a constant of 254 mm.
h. Other compartment metrics can be recorded with the H-point machine positioned as described. Refer to SAE J1100.
Method A (Shoe fits, Knee does not fit)

Position shoe on floor behind the front
seat. Slide shoe forward until it makes
contact with the lower seat structure.
Calculate L48.
Measure L51.
FIGURE A1 - OVERVIEW OF SHORT-COUPLE CONDITION METHOD A
A.1.2 Short-Coupled Seating - Method B (Inadequate floor space to fit the HPM shoe)
a. Follow the general installation procedure through 5.3.5.
b. If the preceding rows seat has fore-aft adjustment capability, then:
1. Place one or more registration marks on the side of the preceding rows seat.
2. Move this seat forward along the seat track travel path until the HPM shoe can be fitted, with the heel as far
rearward as possible.
c. If the preceding rows seat does not adjust, determine the longitudinal (Delta X) displacement required to fit the shoe
on the floor between the seating rows by graphical methods from the drawing, or by mathematical methods in CAD.
d. Record the necessary seat travel used to fit the HPM shoe.
e. Move the preceding rows seat out of the way by using the remaining track travel, the forward tilt or seatback
adjustment, or by physical means.
f. Resume the general installation procedures except:
1. When positioning the shoes on the floor in 5.3.7.3, the shoes should be located as far rearward as possible.
2. When completing the rocking motion in 5.3.12, care should be used to prevent jack-knifing of the legs, and
clam-shelling of the back and seat pans. The shoes are repositioned as far rearward as possible.
g. L48, minimum knee clearance, is best determined graphically on the drawing, or mathematically in CAD by
transferring the physical HPM orientation to either environment, and following the SAE J1100 procedure.
h. Determine L51, effective leg room, by measuring the diagonal distance from the ankle point center to the H-point plus
a constant of 254 mm less the movement of the preceding rows seat recorded in A.1.2.d.
i. Other compartment metrics can be recorded with the H-point machine positioned as described. Refer to SAE J1100.
Method B (Shoe does not fit):
Position shoe in rearmost location to

minimize interference with the seat
(see Shoe Detail).
Calculate L48 (see Knee Detail).
Move seat forward along seat travel, or
if no seat travel, translate horizontally
until shoe will be clear of interference.
Measure L51.
FIGURE A2 - OVERVIEW OF SHORT-COUPLE CONDITION METHOD B
A.1.3 Long-Coupled Seating
a. Follow the general installation procedure through 5.3.6.
b. When positioning the shoes on the floor in 5.3.7.3, place the shoe soles on the foot support with the heel located as
indicated on the drawing. If a foot support is not provided, extend the H-point machine legs to the full limit of the seat
deflection with both shoes flat on the floor. The ankle angle should not exceed 130 degrees.
c. Mark a lateral line at the rear of the heel location.
d. Determine L48, minimum knee clearance, as the distance from the knee joint less 51 mm.
e. Other compartment metrics can be recorded with the H-point machine positioned as described. Refer to SAE J1100.
f. Determine L51:
1. Detach one of the lower leg-shoe assemblies of the H-point machine and place the sole on the floor.
2. Slide the lower leg and shoe forward on the floor until it is obstructed by the seat cushion or support structure and
mark a second line at the rear of the heel.
3. Record the longitudinal distance ( X) between the heel location marked in step c and the current heel location.
4. L51, effective leg room, is best determined graphically on the drawing, or mathematically in CAD by transferring
the physical HPM orientation (from A.1.3.b) and the most forward shoe position (from A.1.3.f.2) to the either
environment, and following the SAE J1100 procedure. It can be approximated by measuring the diagonal
distance between the ankle pivot center and the H-point (from A.1.3.b), plus a constant of 254 mm and the
additional heel point movement ( X).
Method:
Move leg forward until restriction of
ankle angle (130).
Measure L48.
Detach shoe and slide forward
until it makes contact.
FIGURE A3 - OVERVIEW OF LONG-COUPLE CONDITION
A.2 DECISION TREE FOR SHORT- AND LONG-COUPLE CAD PROCEDURES
Figure A4 provides a decision tree for selecting the appropriate CAD method to use for positioning the H-point template
and measuring L48 and L51.
Collect Data
Seating Reference Point Position the CAD Manikin 2-D Template
Torso Angle at the Seating Reference Point and
Depressed Floor Covering design torso angle
Preceding Seat at SgRP and design torso angle
Is the floor covering

No continuous and large Yes
enough to accommodate
the manikin shoe?
Position heel on the rearmost point of Position heel on the floor close to the
the floor with legs attached SgRP X-value with legs attached
Move the shoe forward Does the shoe or

along the depressed No ankle circumference Yes
floor covering contact the
preceding seat?
No
Does the shoe or
ankle No Is the ankle
circumference angle 130?
contact the
preceding seat?
Short Couple Method
Yes Requires leg room penalty
Long Couple Method
Yes
Shoe is at FRP
Indicate manikin position on drawing.
Measure L48-x
Does
Move a copy of the shoe forward until it or the ankle
circumference contacts the preceding rows seat. No preceding Yes
row have
Indicate shoe location on drawing.
seat
Measure Leg Room L51-x.
travel?
Does the Yes

knee or lower
leg interfere? Translate preceding Move preceding seat
seat horizontally forward forward, along the
until the shoe design H-point travel
No interference is cleared. line until the shoe
Short Couple Method interference is cleared.
Standard Method No leg room penalty
Shoe is at FRP Shoe is at FRP Shoe is at FRP

Measure L48-x and L51-x from Measure L48-x (negative) and Subtract preceding seat movement from L51-x
this position L51-x from this position Measure L48-x with no penalty (large negative)
FIGURE A4 - DECISION TREE FOR COUPLE METHODS - 2-D TEMPLATE PLACEMENT FOR 2ND TO NTH ROW
APPENDIX B - DETERMINATION OF CUSHION ANGLE
B.1 BACKGROUND AND DEFINITION OF CUSHION ANGLE
See Section 7 and SAE J1100.
B.2 MEASUREMENT PROCEDURE
Cushion Angle is measured using the H-point machine with torso weights redistributed and lower legs removed to
eliminate any confounding effect of packaging geometry on thigh attitude. See Figure B1 for proper distribution of
weights.
B.2.1 Follow the same installation procedures as described in 5.3.1 through 5.3.4 but with both lower legs removed.
B.2.2 Place the cushion and back assembly with legs removed on the selected seat. Lateral location for the driver is
specified in 5.3.4. Other seated positions are specified in 5.3.7.2 through 5.3.7.4.
B.2.3 Alternately install the two buttock weights on the H-point pivot on the cushion pan. Alternately place two torso
weights next to the buttock weights.
B.2.4 Install the two thigh weights on the cushion pan and level the machine.
B.2.5 Apply a 16 kg (35 lb) load to the push spring on the machine cushion pan.
B.2.6 Add, alternately, four additional torso weights next to the H-point pivot. (All weights are placed on or in the
cushion pan.)
B.2.7 Add, alternately, the remaining two torso weights at the front of the cushion pan. The weights will each lay
propped outwardly in the forward corner of the cushion pan against the thigh weights.
B.2.8 Set the torso angle quadrant to zero, rotate the head room probe to vertical using the torso angle level and lock
it in position. The machine is now prepared for Cushion Angle readout using the hip angle quadrant to measure
the Thigh Centerline angle (Hip angle relative to a vertical Torso angle).
(Cushion Angle, A27) = (90 Degrees - Hip Angle scale reading)
FIGURE B1 - DISTRIBUTION OF WEIGHTS FOR CUSHION ANGLE MEASUREMENT
APPENDIX C - SAE J826 H-POINT MACHINE CALIBRATION INSPECTION
C.1 APPLICATION
This inspection procedure can be used to check calibration of the SAE J826 H-Point Machine. Actual calibration of the
HPM shall be performed by an SAE sanctioned agency.
C.2 BASIC EQUIPMENT
The following equipment is used for checking HPM calibration:
- Flat, level surface (or surface plate) approximately 750 mm wide and 1000 mm long
- One 90-degree angle block at least 500 mm wide and 500 mm high
- One 25 mm diameter rod at least 200 mm long
- 4 back pan shims of thickness 0.5, 1, 2 and 4 mm, height 130 mm, and width 400 mm
- 1 cushion pan shim 4 mm thick, 130 mm high, at least 400 mm wide
- Set of shim gauges at least 125 mm long, thickness range 0.025 to 0.75 mm (e.g., Starrett #667)
- 2 small C-clamps with 75 mm throats, 1 C-clamp with 20 mm throat
- CMM equipment for taking measurements
- Electronic Inclinometer
- Metric scales: 100 mm and 1000 mm (neither scale is required, but they are useful during HPM setup)
- Torque wrench (accurate in 20 to 40 in-lb range) with inch socket
- Two inch open end wrenches
- Weight scale (accurate to +1 lb)
Points used to determine distance measurements shown in Table C1 should be taken with a CMM. Angular
measurements should be taken with either the CMM or the inclinometer.
C.3 GRID SYSTEM
The xyz axis orientations used to record CMM data and establish the tolerance measurements are as follows (Figure C1):
- The origin (0.0.0) is at the H-point.

- Positive x is rearward, positive z is upward and positive y is to the right of the H-point (viewing the HPM from rear).
- The x and y axes are parallel to the flat level surface; the x axis is normal to the vertical surface of the angle block and
the y axis is parallel to the angle block.
- The z-axis is normal to the flat level surface.
FIGURE C1 - MEASUREMENT COORDINATE SYSTEM FOR HPM PANS
This convention should be used for both linear and angular measurements. The flat level surface and 90-degree angle
block are used to position the HPM back and cushion pan. A positive angle in side view is clockwise as viewed from the
left side of the pans. This angle convention is consistent with positive thigh angle and torso angle definitions.
Prior to calibrating the HPM the inclinometer shall be placed on the flat level surface parallel to the x and y axis and set to
zero. The inclinometer should be zeroed prior to each measurement taken.
C.4 H-POINT MACHINE MEASUREMENT LOCATIONS
Most measurements specified in the checking procedures are taken from available points and surfaces on the H-point
machine.
- H1L and H1R divots are the crosshairs on the H-point buttons on each side of the cushion pan.
- The thigh angle land is the top surface of the T-bar housing on the cushion pan.
- The torso angle land is the front surface of the head room probe scale on the back pan with the probe seated against
the adjustment screw. This land parallels the torso line of the HPM (Figure C1).
- The knee pivot center for the leg is the intersection of a longitudinal centerline (parallel to the y-axis) of the square T-bar
and the centerline of the T-bar insert hole (x-axis).
- The ankle pivot center is the center of the bolt head or nut attaching the leg to the shoe.
- The head room probe tip is at the top center of the head room probe.
- The upper and lower leg links are pinned at the 95% settings.
NOTE: The thigh angle land and torso angle land shown in Figure C1 are calibrated surfaces in HPM builds since 2008.
The front face of the left yoke of the torso weight bar will also a calibrated surface for measuring torso angle, if the
HPM is certified for HRMD assessments. Prior to 2008 these surfaces were not calibrated in HPM build or during
HPM calibrations.
C.5 CUSHION AND BACK PAN: MEASUREMENT COORDINATE SYSTEM AND PRELIMINARY ADJUSTMENTS
C.5.1 Set H-point Joint Torque
Torque the nuts on the pivot of the H-point shaft assembly to 30 in-lb (Figure C2). Remove the H-point weight hanger
bushing to gain access to the locking nut. Hold the nut on the other side and torque the locking nut. Once the torque is
set, hand-tighten the H-point weight hanger bushing. Record the torque setting in Table C1.
FIGURE C2 - HPM TORQUE ADJUSTMENT. SOME HPMS MAY DIFFER FROM THIS ILLUSTRATION.
C.5.2 Establish Measurement Coordinate System for HPM Body Pans
Coordinate origin is the H-point. Note that the methods described below can be enhanced by constructing a special
fixturing device containing adjustable surfaces that could reduce or eliminate the need for using shims. Special fixtures
could also be constructed to aid in aligning the HPM axes to the reference planes established by the flat level surface and
90 degree angle block.
C.5.2.1 Cushion Pan (x and y axes)
Use CMM equipment to align the HPM to the Y- and Z-planes defined by the flat level surface and the vertical angle block
(Figure C3).
- Place the HPM cushion and back pan assembly on the flat level surface.
- Slide the cushion pan and back pan assembly against the vertical angle block, holding the back pan approximately
vertical. If the back pan contacts the vertical block before the cushion pan, set the torso angle to 0 (vertical) with the
back pan resting against the vertical block.
- Support the front of the cushion pan using the 25 mm rod such that the thigh angle land (top of the T-bar housing) is
level as checked with the inclinometer. Record values for 6a and 6b in Table C1. See Figure C3.
- Align the HPM x-axis, which is a line from the front center of the T-bar, through the HPM H-point, perpendicular to the
vertical angle block, and parallel to the flat level surface. Adjust the left and right H-point divots by rotating the HPM until
2a=2b. Record these dimensions.
- Level HPM y-axis, which is a line through the left and right H-point divots. Measure and record the heights of the left
and right H-point buttons above the flat level surface (3a and 3b in Table C1 and shown as #3 in Figure C3). If the left
and right H-point buttons are not equidistant above the flat level surface (i.e., measurements 3a and 3b are not equal),
shim the cushion pan until 3a=3b using the appropriate shim gauge from the set of shim gauges. The HPM y-axis
should now be parallel to the angle block and to the flat level surface plate.
FIGURE C3 - HPM CUSHION AND BACK PAN SETUP
C.5.2.2 Check Cushion Pan Bubble Level
Verify that the bubble level on the cushion pan reads level (Figure C1). If not, complete steps 5.2.3 and 5.2.4 before
adjusting the bubble level, since accessing the underside of the cushion pan will undo the measurement setup.
C.5.2.3 Check x-axis Inclination
Take measurements 4a-4d and calculate 4i-4m in Table C1. These measurements verify that the thigh line (x-axis in
inspection procedure) is horizontal, and that the knee pivot is aligned with the H-point.
C.5.2.4 Check Back Pan Verticality and Offset to Cushion Pan
Prior to recording measurements, check the offset between the back of the back pan and the back of the cushion pan.
Also check that the mid-back flat surface is vertical. Design intent is 0 offset. The back pan may be up to 4 mm forward,
but not rearward of the cushion pan when the torso angle is 0 degrees (vertical). These checks are made as follows.
Shim the back pan until contact is made with the flat vertical area of the back pan between the attaching bolts. If
necessary, rotate the back pan until the flat area is tangent to the shim (visual inspection). Using shim gages, measure
the offset of mid-back surface between the top, middle and bottom back pan bolts. Offset (5a) is measured between the
mid-rear of the cushion pan and the back pan surface at the middle attachment bolt. The difference between the top and
bottom attachment bolts on the back (5b) is used to verify verticality of the flat portion of the back pan. Record these
values in Table C1.
If either the offset or the flat part of the HPM back pan is not within spec, remove the six attaching bolts and add washers
between the metal and inside of the fiberglass shell to reposition the back pan to specification. The flat part of the back
pan (the surface between the attaching bolts in the lower, mid-back) should be firmly against and tangent to the vertical
angle block or a shim(s).
After adjusting the back pan surface or the cushion pan bubble level to specification, repeat step 5.2.1-5.2.3. The final
offset of the back pan to cushion pan is the difference between the shim thicknesses for the cushion and back pans.
C.5.2.5 Back Pan (HPM z-axis)
Set the headroom probe against its vertical stop. Place inclinometer on the torso angle land of the head room probe (the
front surface of the head room scale). It should read 90 degrees. If not, adjust the head room probe alignment set screw
to attain a vertical condition. This establishes the HPM z-axis.
C.6 MEASUREMENTS AND ACCEPTABLE TOLERANCES
C.6.1 Back Pan and Cushion Pan
Recheck the alignments in 5.2 to ensure that the HPM is still properly set up before continuing with measurements.
Table C1 lists the measurements to be taken and the acceptable tolerances. Cushion and back pan measures are
illustrated in Figure C4.
FIGURE C4 - HPM CUSHION AND BACK PAN MEASUREMENTS
C.6.1.1 Check Hip Angle Scale
The hip angle scale (7d) should read within +1.0 degree of 90 degrees. If not, the hip angle scale should be re-positioned
to read 90 degrees. On some HPMs this scale is not adjustable. Record any scale reading error. If the scale cannot be
adjusted to meet specification, hip angle should be determined from inclinometer readings of torso and thigh angle lands.
C.6.1.2 Check Torso Angle Bubble Level
Verify that the torso angle scale (7e, 7f) reads within +1.0 degree of 0 when the torso angle bubble level indicates level.
Neither the scale markings nor the bubble level are adjustable. Record and mark the scale reading error. Future readings
of torso angle should be made using the inclinometer and calibrated land. The scale markings may be removed at the
users discretion.
C.6.1.3 Adjust Bubble Level Inclinometer
Install the lateral bubble level inclinometer thats used when rocking the HPM side-to-side. Adjust so it reads 0 degrees.
Both the cushion pan bubble level and the bubble level inclinometer are now aligned to the HPM y-axis.
C.6.1.4 Check Torso Weight Bar
Measurements 8a-8d from H-point to torso weight bar are not critical for measuring H-point. They are important for
measurements taken with the head restraint measuring device (HRMD) because the HRMD attaches to the torso weight
bar (see Appendix D). These measurements should be taken at 25mm from the inboard end of each torso weight bar,
which approximates the mounting area of the HRMD; use a circle method with CMM to locate the center of the bar. Prior
to 2008 these dimensions were not controlled in HPM build. These dimensions will be controlled in future HPM builds if
the HPM is intended for use with the HRMD. The tolerances for 8a-8d given in Table C1 are temporary placeholders until
more and better data are available.
C.6.1.5 Check Pan Widths
The maximum cushion and back pan widths, measurements 10a and 10b in Table C1, are shown in Figure C6. These
two specifications apply to HPM builds since 1989 that have a serial number Txxx (or pan replacements on older HPMs).
Prior to 1989 the maximum width of both pans was slightly greater. The maximum width of the cushion pan was 385 mm
excluding the H-point buttons. The maximum width of the back pan was 395 mm.
C.6.2 Head Room Probe
Using the set-up in 6.1.1 set the head room probe to read 39 inches. Determine the measurements as described in
Table C1 (11a through 11c).
C.6.3 Leg and Shoe Assembly
Remove the T-bar from the cushion pan and insert each leg on the T-bar. Support the leg and T-bar for measurement as
shown in Figure C5. Set the back of the leg to 90 degrees and the T-bar to horizontal. Record the knee and ankle angle
scale readings (left leg codes: 12a and 12b) for both the inboard and outboard scales on each leg, and the other length
measurements listed in Table C1 (left leg: 13a, b, c, d).
Check for excessive rotational effort about the ankle joint as follows (Figure C6). Suspend the lower leg assembly
vertically above the floor. The foot should rotate freely under its own weight without excessive lateral play.
Check for excessive rotational effort about the knee joint as follows (Figure C6). Remove the thigh bar from the manikin
and insert it into the knee pivot as far as possible. With the lower leg held vertically and the thigh bar horizontal, the thigh
bar should rotate under its own weight when released. Also, with the lower leg and thigh bar held horizontally, the thigh
bar should rotate under its own weight when released.
FIGURE C5 - LEG AND SHOE SETUP
FIGURE C6 - ANKLE AND KNEE JOINT EFFORT CHECK
C.6.4 Weights
Determine the weights of the components shown in Figure C7 and described in Table C1 (15a through 15d).
FIGURE C7 - HPM WEIGHTS
TABLE C1 - HPM DIMENSIONS AND TOLERANCES

(ITEM NUMBERS IDENTIFY A MEASUREMENT SHOWN IN FIGURES C1-C7)
H-Point Machine ____________________________________________ Date_______________________
Item Description Specification Measurement
Back Pan and Cushion Pan (Figures C1 - C4)

1 H-point joint torque 30 +/-4 in-lb
2a H1L divot rearward to vertical angle block surface 134.9 +/-2 mm

2b H1R divot rearward to vertical angle block surface 134.9 +/-2 mm
2c Mean H-point (center) rearward to vertical angle block surface 134.9 +/-2 mm
3a H1L divot height from level surface 97.6 +/-2 mm
3b H1R divot height from level surface 97.6 +/-2 mm
Shim under cushion pan until 3a=3b
3c H1 divot height from level surface (mean of 3a and 3b) 97.6 +/-2 mm
3d Cushion pan bubble level bubble reads
level
4a (b) Left (Right) knee pivot to H1L (H1R), x horizontal distance for Left Right
95% leg length
455.7 +/-2 mm
4c (d) Left (Right) knee pivot height from level surface, z 95% leg 97.6 +/-2 mm
4e (f) Left (Right) knee pivot to H1L (H1R), x - 50% leg 431.5 +/-2 mm
4g (h) Left (Right) knee pivot to H1L (H1R), x - 10% leg 407.7 +/-2 mm
4i Knee pivot x-distance from H-point (mean of 4a and 4b) 455.7 +/-2 mm
4j Knee pivot height from level surface (mean of 4c and 4d) 97.6 +/-2 mm
4k Difference in height between mean H1 and knee pivot (4j-3c) 0 +/- 1 mm
4m x-axis side view angle [arctan(4k/4i)] 0 +/-0.2
5a Back pan to cushion pan offset (value is positive if back pan is Initial Final
forward of cushion pan); measure to middle bolts of lower back
at C/L 0 +4/-0 mm
5b Flat surface on lower mid-back; measure offset difference < 1.1 mm

between upper and lower bolts at lower back C/L
(90 +/-0.5)
Note: After adjusting cushion pan bubble level or back pan offset/verticality, re-establish the
measurement coordinate system. Retake measurements 2-5.
6a Thigh angle land (inclinometer on T-bar housing) 0 +/-0.1
6b Thigh angle (from CMM points on land) 0 +/-0.2
7a Torso angle land (inclinometer on head room probe scale) 90 +/-0.1
7b Torso angle (from CMM points on land) 90 +/-0.2
7c Hip angle (from CMM points on torso and thigh angle lands) 90 +/-0.25
Hip angle = torso angle thigh angle
7d Hip angle scale reading 90 +/-1
7e Torso angle bubble level on hip quadrant bubble reads
level
7f Torso (back) angle scale reading (forward is a negative angle) 0 +/-1
7g Torso angle (inclinometer on land--left side torso weight yoke) 90 +/-0.5

7h Torso angle (from CMM points on land--left torso weight yoke) 90 +/-0.5
1
8a Mean H-pt to left inboard center of torso weight bar, Z 356.4 +/-1 mm
Note: Measurements 8a-d are made at 25 mm from inboard end
of torso weight bar. Use CMM circle method to find center.
8b1 Mean H-pt to left inboard center of torso weight bar, X 0 +/-1 mm
8c1 Mean H-pt to right inboard center of torso weight bar, Z 356.4 +/-1 mm
1
8d Mean H-pt to right inboard center of torso weight bar, X 0 +/-1 mm
9 Lateral bubble level inclinometer reading 0 +/-1
2
10a Cushion pan width at H-point (3.8 mm button depth not included) 379 +/-2 mm
2
10b Back pan width, maximum (Figure C6) 388 +/-2 mm
Head Room (Figure C4)
11a Head room probe height at 39 inch setting above surface plate at 986.2 +/-2 mm
H-point (subtract 97.6 if measured from H-point)
(888.6 from H-pt)
11b Tip of head room probe fore aft of H-point +/-5 mm

11c Tip of head room probe each side of H-point +/-5 mm
Lower Legs (Figures C5, C6) Left Right
12a (c) Left (Right) knee angle scale inboard (I) and outboard sides I
90 +/-1
(back of leg set at 90 degrees and T-bar horizontal) O
I
12b (d) Ankle (foot) angle scale 96.5 +/-1
O
13a (e) Left (Right) ankle pivot to level surface 107.2 +/-2 mm
13b (f) Left (Right) knee pivot to ankle pivot (95%) 458.7 +/-2 mm
13c (g) Left (Right) knee pivot to ankle pivot (50%) 417.1 +/-2 mm
13d (h) Left (Right) knee pivot to ankle pivot (10%) 392.7 +/-2 mm
14a Left (Right) ankle pivot rotates freely Yes -- If No,
repair.
14b Left (Right) knee pivot rotates freely Yes -- If No,
repair.
Machine Weights (Figure C7)
15a Cushion and Back Pans (includes inclinometer but no weights) 43.4 +/-2.7 lb
15b Lower leg and shoe X 2 19.4 +/-0.5 lb
15c Torso and buttock weight X 10, Thigh weight X 2, Leg weight X 2 106.8 +/-0.7 lb
15d Total weight 169.6 +/-3.4 lb
1
Not a controlled dimension in HPM builds unless the HPM is intended for use with an HRMD. This is a key
dimension for the HRMD.
2
HPMs built prior to 1989 have slightly wider cushion and back pans and do not meet this tolerance specification.
For these HPMs, the nominal maximum cushion pan width is 385 mm. For the back pan the nominal width is
395 mm.
HPM calibrated for use with HRMD (Figures C1 and C4)

5a Back pan to cushion pan offset (value is positive if back pan is 0 +1/-0 mm
forward of cushion pan); measure to middle bolts of lower back
at C/L
7g Torso angle (inclinometer on land--left side torso weight yoke) 90 +/-0.1
7h Torso angle (from CMM points on land--left torso weight yoke) 90 +/-0.1
8a Mean H-pt to left inboard center of torso weight bar, Z 356.4 +/-1 mm
Note: Measurements 8a-d are made at 25 mm from inboard end
of torso weight bar. Use CMM circle method to find center.
8b Mean H-pt to left inboard center of torso weight bar, X 0 +/-1 mm
8c Mean H-pt to right inboard center of torso weight bar, Z 356.4 +/-1 mm
8d Mean H-pt to right inboard center of torso weight bar, X 0 +/-1 mm
APPENDIX D - HEAD RESTRAINT MEASURING DEVICE (HRMD)
D.1 BACKGROUND
The HRMD attaches to the torso weight bar of the HPM and is used to assess head restraint backset and height. These
measurements are cited in a federal regulation on head restraints (FMVSS 202a).
D.2 INSTALLATION PROCEDURE
The HRMD installation procedure used by IIHS is available at

http://www.iihs.org/ratings/protocols/pdf/head_restraint_procedure.pdf
The HRMD installation procedure used by NHTSA is available at
www.nhtsa.dot.gov/staticfiles/DOT/NHTSA/Vehicle%20Safety/Test%20Procedures/Associated%20Files/TP-202aS-00.pdf
The two procedures are similar but not identical.
In order to keep measurement variability as low as practicable, the SAE HADD Committee strongly recommends that
each measurement facility dedicate a single HPM and a single HRMD (acting as a test pair) when making head restraint
assessments with the HRMD. The HPM and HRMD should be calibrated as a system.
Disassembling and reassembling a calibrated HPM or HPM/HRMD system can affect its calibration. If an HPM is used for
taking HRMD measurements, and then disassembled and reassembled for performing conventional H-point installations,
the user should confirm that the HPM still meets the calibration specifications of Appendix C. If the HPM is subsequently
used with the HRMD, calibration of the HPM/HRMD system should again be verified.
D.3 CALIBRATION PROCEDURE
At the time of publication there was no SAE sanctioned procedure to calibrate the HRMD together with the SAE J826
H-Point Machine. A calibration procedure is under development and may be included in a future SAE standard. An HPM
calibrated for use with a given HRMD will likely have a unique certification marking.

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What is the purpose of the SAE J826 standard?

What is the purpose of the SAE J826 standard?

What changes were made in the 2008 revision of the SAE J826 standard?

What changes were made in the 2008 revision of the SAE J826 standard?

SURFACE J826 NOV2008

Superseding J826 MAR2008

Devices for Use in Defining and Measuring Vehicle Seating Accommodation

Other changes included:

- 10 year phase-out period for the HPM

4. H-POINT TEMPLATEDESCRIPTION, APPLICATION, AND POSITIONING PROCEDURE .................. 5

5. H-POINT MACHINEDESCRIPTION, APPLICATION, AND INSTALLATION PROCEDURE................... 8

6. SHORT-COUPLED SEATING CONDITION............................................................................................... 13

7. LONG-COUPLED SEATING CONDITION ................................................................................................. 13

8. DETERMINATION OF CUSHION ANGLE ................................................................................................. 13

9. H-POINT MACHINE AND TEMPLATE FABRICATION.............................................................................. 13

10. CALIBRATION OF THE H-POINT MACHINE ............................................................................................ 13

APPENDIX A INSTALLATION PROCEDURE FOR SHORT- AND LONG-COUPLED SEATING ................................... 15

FIGURE 1 H-POINT TEMPLATE ................................................................................................................................... 6

TABLE 1 LEG SEGMENT LENGTH .......................................................................................................................... 10

2.1 Applicable Publications

2.1.1 SAE Publications

SAE J1100 Motor Vehicle Dimensions

2.2 Related Publications

2.2.1 SAE Publications

SAE J1516 Accommodation Tool Reference Point

SAE J1517 Driver Selected Seat Position

SAE J2732 Motor Vehicle Seat Dimensions

3.1 Accelerator Heel Point, AHP

3.2 Ankle (Foot) Angle, A46

3.3 Ball of Foot, BOF

3.4 Cushion Angle, A27

3.5 Floor Reference Point, FRP

3.7 Heel of Shoe

3.8 Hip Angle, A42

3.9 Knee Angle, A44

3.10 Seating Reference Point, SgRP

3.11 Shoe Plane

3.12 Thigh Centerline

3.13 Thigh (Cushion) Line

3.14 Torso (Back) Angle, A401

3.15 Torso Line

4. H-POINT TEMPLATEDESCRIPTION, APPLICATION, AND POSITIONING PROCEDURE

4.2 ApplicationAids in displaying the following:

4.3 Positioning Procedure for physical template (Figure 1)

FIGURE 1 - H-POINT TEMPLATE

4.3.2 Front SeatDriver Position

4.3.3 Front SeatDriver Position

4.3.4 Second RowLeft Side Occupant Position

4.3.5 Third RowLeft Side Occupant PositionForward Facing

4.3.6 Third RowLeft Side Occupant PositionRearward Facing

4.3.7.4 Lock this quadrant in place.

4.4 Positioning Procedure for CAD template (Figure 2)

4.4.1 Use of optional shoe bottom

FIGURE 2 - CAD VERSION OF H-POINT TEMPLATE

4.4.3.2 Install the CAD template as described in 4.4.2.

5. H-POINT MACHINEDESCRIPTION, APPLICATION, AND INSTALLATION PROCEDURE

FIGURE 3 - H-POINT MACHINE

FIGURE 4 - H-POINT MACHINE

TABLE 1 - LEG SEGMENT LENGTH