User’s Manual

DIELECTRIC CONSTANT OF SOLIDs & LIQUIDS

Model: DSL-01
(Rev:13-10-18)

Manufactured by . .
SES Instruments Pvt. Ltd.
452 Adarsh Nagar
Roorkee - 247 667, UK, INDIA
Ph.: +91-1332-272852, 277118
Fax: +91-1332-274831
Email: ses@sestechno.com
sestechno.india@gmail.com ISO 9001:2015
Website: www.sestechno.com Certified Company
 CONTENTS

Section Page

1. Copyright, Warranty, and Equipment Return 1

2. Safety Information 2
 General Safety Summary
 Symbols
3. Unpacking and Inspecting the Instrument 4
4. Storing and Shipping the Instrument 4
5. Power Considerations 4
 Replacing the Fuse
 Connecting to Power Line
 Turning Power ON
6. Cleaning the Instrument 6
7. Introduction 7
8. Packing List 8
9. Brief Description of the Apparatus 9
10. Experimental Procedure 10
11. Observation & Calculations 10
12. Typical Result 11
13. Precautions 12
14. Reference 12
15. Technical support 13
 COPYRIGHT AND WARRANTY

Please – Feel free to duplicate this manual subject to the copyright restriction given below.

COPYRIGHT NOTICE

The SES Instruments Pvt. Ltd Model DSL-01 Study of Dielectric Constant of Solids &
Liquids manual is copyrighted and all rights reserved. However, permission is granted to
non-profit education institutions for reproduction of any part of this manual provided the
reproduction is used only for their laboratories and are not sold for profit. Reproduction under
any other circumstances, without the written consent of SES Instruments Pvt. Ltd is
prohibited.

LIMITED WARRANTY

SES Instruments Pvt. Ltd warrants this product to be free from defects in materials and
workmanship for a period of one year from the date of shipment to the customer. SES
Instruments Pvt. Ltd will repair or replace, at its option, any part of the product which is
deemed to be defective in material or workmanship. This warranty does not cover damage to
the product caused by abuse or improper use. Determination of whether a product failure is
the result of manufacturing defect or improper use by the customer shall be made solely by
SES Instruments Pvt. Ltd. Responsibility for the return of equipment for warranty repair
belongs to the customer. Equipment must be properly packed to prevent damage and shipped
postage or freight prepaid. (Damage caused by improper packaging of the equipment for
return shipment will not be covered by the warranty). Shipping costs for returning the
equipment, after repair, will be paid by SES Instruments Pvt. Ltd.

EQUIPMENT RETURN

Should this product have to be returned to SES Instruments Pvt. Ltd, for whatever reason,
notify SES Instruments Pvt. Ltd BEFORE returning the product. Upon notification, the return
authorization and shipping instructions will be promptly issued.

Note : No equipment will be accepted for return without an authorization.

When returning equipment for repair, the units must be packed properly. Carriers will not
accept responsibility for damage by improper packing. To be certain the unit will not be
damaged in shipment, observe the following rules:
1. The carton must be strong enough for the item shipped.
2. Make certain there is at least two inches of packing material between any point on the
apparatus and the inside walls of the carton.
3. Make certain that the packing material can not displace in the box, or get compressed,
thus letting the instrument come in contact with the edge of the box.

SES Instruments Pvt. Ltd. DSL-01 Page 1

SAFETY INFORMATION

This Section addresses safety considerations and describes symbols that may appear on the
Instrument or in the manual.
A Warning Statement identifies conditions or practices that could result in injury or death. A
Caution statement identifies conditions or practices that could result in damage to the
Instrument or equipment to which it is connected.

Warning
To avoid electric shock, personal injury, or death, carefully read the information in
Table-1, “Safety Information,” before attempting to install, use, or service the
Instrument.

GENERAL SAFETY SUMMARY

This equipment is Class 1 equipment tested in accordance with the European Standard
publication EN 61010-1.
This manual contains information and warnings that must be observed to keep the Instrument
in a safe condition and ensure safe operation.
To use the Instrument correctly and safely, read and follow the precautions in Table 1 and
follow all safety instructions or warnings given throughout this manual that relate to specific
measurement functions. In addition, follow all generally accepted safety practices and
procedures required when working with and around electricity.

SYMBOLS

Table 2 lists safety and electrical symbols that appear on the Instrument or in this manual.
Table 2. Safety and Electrical Symbols

Symbols Description Symbols Description

Risk of danger. Important

Earth ground
information. See Manual.

Hazardous voltage. Voltage

>30Vdc or ac peak might be Potentially hazardous voltage
present.
Do not dispose of this product as
Static awareness. Static unsorted municipal waste.
discharge can damage parts. Contact SES or a qualified
recycle for disposal.

SES Instruments Pvt. Ltd DSL-01 Page 2

 Table 1. Safety Information

Warning

To avoid possible electric shock, personal injury, or death, read the following before
using the Instrument:

 Use the Instrument only as specified in this manual, or the protection provided
by the Instrument might be impaired.
 Do not use the Instrument in wet environments
 Inspect the Instrument in wet environments.
 Inspect the Instrument before using it. Do not use the Instrument if it appears
damaged.
 Inspect the connecting lead before use. Do not use them if insulation is damaged
or metal is exposed. Check the connecting leads for continuity. Replace damaged
connecting leads before using the Instrument.
 Whenever it is likely that safety protection has been impaired, make the
Instrument inoperative and secure it against any unintended operation.
 Have the Instrument serviced only by qualified service personnel.
 Always use the power cord and connector appropriate for the voltage and outlet
of he country or location in which you are working.
 Never remove the cover or open the case of the Instrument before without first
removing it from the main power source.
 Never operate the Instrument with the cover removed or the case open.
 Use only the replacement fuses specified by the manual.
 Do not operate the Instrument around explosive gas, vapor or dust.
 When servicing the Instrument, use only specified replacement parts.
 The equipment can remain Switched on continuously for five hours
 The equipment must remain Switched off for at least fifteen minutes before
being switched on again.
 The equipment is only for the intended use
 Use the equipment only as specified in this manual.

SES Instruments Pvt. Ltd. DSL-01 Page 3

Unpacking and Inspecting the Instrument

Every care is taken in the choice of packing material to ensure that your Instrument will reach
you in perfect condition. If the Instrument has been subject to excessive handling in transit,
there may be visible external damage to the shipping container and packing material for the
carrier’s inspection.
Carefully unpack the Instrument from its shipping container and inspect the contents for
damaged or missing items. If the Instrument appears damaged or something is missing,
contacts the carrier and SES immediately. Save the container and packing material in case
you have to return the Instrument.

Storing and Shipping the Instrument

To prepare the Instrument for storage or shipping, if possible, use the original shipping
container alongwith thermocoal corners, as it provides shock isolation for normal handling
operations. If the original shipping container is not available, use any good cardboard box
which is at least 2-3 inches bigger than the instrument on all sides, with cushioning material
(thermocoal or styrofoam etc) that fills the space between the Instrument and the side of this
box.
To store the Instrument, place the box under cover in a location that complies with the
storage environment specification described in the “Environment Sections” below.

Environment

Temperature
Operating …………………………………. 0°C to 50°C
Storage …………………………………… 40°C to 70°C
Warm Up …………………………………15 min to full uncertainty specification

Relatively Humidity (non-condensing)

Operating ………………………………….Uncontrolled (<10°C)
<90 % (10°C to 30°C)
<75 % (30°C to 40°C)
<45 % (40°C to 50°C)
Storage………………………………….. -10°C to 60°C <95 %

Power Considerations

The Instrument operates on varying power distribution standards found throughout the world
and must be set up to operate on the line voltage that will power it. The Instrument is packed
ready for use with a line voltage determined at the time of ordering.

Replacing the Fuses

The Instrument uses one fuse to protect the line-power input and two fuses to protect current-
measurement inputs.

SES Instruments Pvt. Ltd. DSL-01 Page 4

Line-Power Fuse

The Instrument has a line-power fuse in series with the power supply. Table 3 indicates the
proper fuse for each of the four line-voltage selections. The line-power fuse is accessed
through the real panel.
1. Unplug the power cord.
2. Rotate the fuse holder cap to the right until the fuse POPS out.
3. Remove the fuse and replace it with a fuse of an appropriate rating for the selected
line-power voltage. See Table 2.

Warning
To avoid electric shock or fire, do not use makeshift fuses or short-circuit the fuse holder.
Table 2. Line Voltage to Fuse Rating

Line Voltage Selection Fuse Rating

220/ 240 V 1A, 250V (Slow blow)

100/ 120 V 2A, 250 V (Slow blow)

Connecting to Line Power

Warning
To avoid shock hazard, connect the factory supplies three conductor line power cord to a
properly grounded power outlet. Do not use a two-conductor adapter or extension cord,
as this will break the protective ground connection. If a two conductor power cord must
be used, a protective grounding wire must be connected between the ground terminal
and earth ground before connecting the power cord or operating the Instrument.

1. Verify that the Line voltage is set to the correct setting.

2. Verify that the correct fuse for the line voltage is installed.

3. Connect the power cord to a properly grounded three-prong outlet. See Figure 1
for line-power cord types available from SES. Refer to Table 2 for description of
the line-power cords.

Plug-1 Plug-2 Plug-3

Figure 1. Line-Power Cord Types Available from SES

SES Instruments Pvt. Ltd. DSL-01 Page 5

 Table 3. Line-Power Cord Types Available from SES

Type Voltage/Current SES Model Number

India 240 V/ 5 A Plug-1

North America 120 V/15 A Plug-2

Universal Euro 220 V/16 A Plug-3

Turning Power On

The On-Off switch on the front panel when points towards “ON” signs, indicates that the
equipment has been switched on.

Cleaning the Instrument

Warning

To avoid electric shock or damage to the Instrument, never get water inside the Instrument.

Caution

To avoid damaging the Instrument’s housing, do not apply solvents to the Instrument.
If the Instrument requires cleaning, wipe it down with a cloth that is lightly dampened with
water or a mild detergent. Do not use aromatic hydrocarbons, alcohol, chlorinated solvents,
or methanol-based fluids when wiping down the Instrument.

SES Instruments Pvt. Ltd. DSL-01 Page 6

 - + - + - +

Charge - + - + - +
+Q -Q
- + - + - +

- + - + - +

- + - + - +

- + - + - +

Electric - + - + - +
field E
- + - + - +

- + - + - +

Dielectric

Polarised molecules

Figure 1
DIELECTRIC CONSTANT OF SOLIDS & LIQUIDS DSL-01
Measurement of dielectric constant of non-conducting solids & liquids

INTRODUCTION
Dielectric or electrical insulating materials are the substances in which electrostatic
field can persist for long times. When a dielectric is placed between the plates of a capacitor
and the capacitor is charged, the electric field between the plates polarizes the molecules of
the dielectric (Figure 1). This produces concentration of charge on its surface that creates an
electric field which is antiparallel to the original field (which has polarized the dielectric).
This reduces the electric potential difference between the plates. Considered in reverse, this
means that, with a dielectric between the plates of a capacitor, it can hold a larger charge. The
extent of this effect depends on the dipole polarizability of molecules of the dielectric, which
in turn determines the dielectric constant of the material.

The electrons in the molecules shift toward the positively charged plate. The molecules then
create a leftward electric field that partially annuls the field created by the charged plates.
(The air gap is shown for clarity; in a real capacitor, the dielectric is in direct contact with the
plates.)

The method for determination of dielectric constants of liquids consists in the successive
measurement of capacitance, first in a vacuum, and then when the capacitor is immersed in
the liquid under investigation. A cylindrical capacitor has been used for liquid samples and
different size parallel plate capacitors for solid samples.

Parallel Plate Capacitor:

The capacity of a parallel plate capacitor is given by

 0A
C farad, (1)
d

where A is plate area and d is distance between the plates. It is assumed that the dielectric
completely fills the space between the capacitor plates.

Cylindrical Capacitor:

The capacitance per unit length of a long cylindrical capacitor immersed in a medium of
dielectric constant k is given by

2 0
C   farad/m. (2)
ln r2 r1 
Here  0  8.854  10 12 C2m-2N-1 is permittivity of free space, r1 is external radius of the
inner cylinder and r2 is internal radius of the outer cylinder.

In actual practice, there are errors due to stray capacitances at the ends of the cylinders and
the leads. In any accurate measurement, it is necessary to eliminate these. It has been done in
the following way:

SES Instruments Pvt. Ltd. DSL-01 Page 7

 Capacitance
Measurement

Figure 2a: Coaxial Cylinder Set-up (CCS)

Dielectric Measurement in Liquids

Mo de l: DML -0 1

Low Capacitance
100.32 pf

Zero Set

SES Instruments Pvt. Ltd.

Roorkee

ON

Figure 2b
Dielctric Measurement in Solids & Liquids (Non Conducting)
Model: DSL-01
Consider a cylindrical capacitor of length L (in meter) filled to a height h  L with a liquid
of dielectric constant  . Its total capacitance is given by

2 0
C  h   0 L  h  C s . (3)
ln r2 r1 

Here  0 is the dielectric constant of air and C s is sum total of stray capacitances. A
simplification of Eq.(2) leads to

2 0
C    0  h  C 0 , (4)
ln r2 r1 
where
2 0
C0  Cs   0L .
ln r2 r1 
Eq. (3) shows that the measured capacity C is a linear function of h (the height upto which
the liquid is filled in the capacitor). If we vary the liquid height h , and measure it, together
with the corresponding capacitance C , the plot of the data should be a straight line. The
slope

2 0
dC
    0  farad/m (5)
dh ln r2 r1 
will yield a value for  if  0 , r1 and r2 are known. The uncertainty due to C s has thus
been eliminated.

PACKING LIST
1. Dielectric Constant of Solids & Liquids, DSL-01: One
2. Sample Jar (Glass): One
3. Sample (Solid): Glass Plate, Bakelite Sheet, Teflon, PZT (Lead Zirconate Titanate)
4. Sample (Liquid): Carbon Tetrachloride (500ml)

SES Instruments Pvt. Ltd. DSL-01 Page 8

BRIEF DESCRIPTION OF THE APPARATUS

1. (a) Probes Arrangement for Solids

It consists of two circular parallel plate setups of diameters 10mm and 50mm to cater
to smaller and bigger samples respectively. One of the plates of the pair is fixed on
the mount while the other can be moved up and down for inserting the sample
between the plates and making the metallic plate surfaces touch the dielectric sample
surface.

(b) Probes Arrangement for Liquids

It consists of two polished brass cylinders fixed coaxially using threaded insulating
gaskets at the two ends (Figure 2a). These gaskets have holes, in the lower one for
allowing the experimental liquid to flow in between the cylinders, and in the upper
one for communication with the atmosphere. Care has been taken to make the
cylindrical electrodes of uniform cross section. This arrangement is mounted
vertically and can be moved up and down with a rack-and-pinion set-up. It is put in a
vessel containing the experimental liquid. The outer surface of the outer cylinder has a
vertical scale to measure the height of the liquid with in the cylinders. Proper leads are
provided for connection to the Capacitance Meter.

2. Samples
(a) Solids: Glass Plate, Bakelite Sheet, Teflon, PZT (Lead Zirconate Titanate)
(b) Carbon Tetrachloride (CCl4) - supplied with the setup

Other non conducting liquids such as acetone, ethyl alcohol, methanol, glycerol etc.
can also be used for measurement.

3. Digital Capacitance Meter

This is compact direct reading microcontroller based high resolution instrument for
the measurement of capacitance of the sample. It has facility of auto-zeroing.
Specifications
Range : 0 pf – 50 f auto range

Resolution : 0.01 pf

Display : 16 x 2 LCD display with back light

Accuracy : Better than 1%

Zero setting : Push button zero setting

SES Instruments Pvt. Ltd. DSL-01 Page 9

EXPERIMENTAL PROCEDURE

SOLID SAMPLE:

The upper plate of the appropriate parallel plate capacitor of the arrangement for solids
is raised by turning the top screw anticlockwise to keep/ insert the sample. The plate is then
lowered by turning the top screw clockwise till the capacitor plates touch the sample surface.
The arrangement is then connected to the Digital Capacitance Meter. The Meter is switched
on and the reading is recorded.

LIQUID SAMPLE:

The glass container is put on the stand below the Coaxial Cylinder Set-up (CCS) as
shown in Figure 2b. The container is filled with the experimental liquid up to a height of
about 12 cm. The CCS is now lowered until the liquid touches the zero mark on the scale.
The Capacity Meter is now adjusted to zero value by pushing zero set button for about a
second (pressing it for longer duration will automatically set it to Auto Calibration mode,
which is not desirable for this experiment). Remember, the result depends not on the actual
value of capacitance, but on its variation with the height of the liquid. The CCS is then
lowered in steps of 1 cm and the readings on the Capacity Meter are taken and recorded.

TYPICAL OBSERVATIONS, CALCULATIONS AND RESULTS

SOLID SAMPLE:

(1) Room temperature: 26oC

(2) Diameter of smaller capacitor plates: 10.0mm
(3) Diameter of bigger capacitor plates: 50.0mm
(4) Thickness of lead zirconate titanate Pellet: 2.55mm
(5) Thickness of bakelite sheet sample = 1.5mm
(6) Thickness of glass plate sample = 1.5mm
(7) Thickness of teflon sample = 1.0mm

SES Instruments Pvt. Ltd. DSL-01 Page 10

Capacity Measurement

Sr. No. Sample C (pF)

1 PZT 909.15
(Lead Zirconate Titanate)
2 Glass 58.57
3 Bakelite 46.97
4 Teflon 32.28

C d  46 .97  10 -12  1.5  10 -3

 Bak    4.053
 0A 8.854  10 -12  625  3.141  10 -6
C d  909 .15  10 -12  2.50  10 -3
 P ZT    3269 .1
 0A 8.854  10 -12  25  3.141  10 -6
C d  58 .57  10 -12  1.5  10 -3
g    5.055
 0A 8.854  10 -12  625  3.141  10 -6
C d 
32 .28  10 -12  1.00  10 -3
t    1.86
0A 8.854  10 -12  25  3.141  10 -6
Liquid Sample:
Sample: Carbon Tetrachloride (CCl4)
Dielectric Constant of free air (0): 1.0059
External radius of the inner cylinder: 25.4 mm
Internal radius of the outer cylinder: 30.6 mm
Capacity Measurement:

S.No. Liquid Level (cm) Capacity (pf)

1 0.0 0.00
2 1.0 4.69
3 2.0 9.38
4 3.0 13.93
5 4.0 18.41
6 5.0 22.86
7 6.0 27.27
8 7.0 32.07
9 8.0 35.52

SES Instruments Pvt. Ltd. DSL-01 Page 11

 1. A plot of Capacitance v/s Liquid height is shown in Fig. 3.

2. The graph is linear. Its slope dC dh is measured. For the present readings it comes
out to be 3.67 pf/cm = 3.67  10- 10 f/m.

Using Eq.(4),
  0 
dC dh ln r r1 
20
2

 30 .0 
4.444  10 -10  ln 
 25 .4   4.444  10  0.166  1.327
-10

2  3.141  8.854  10 -12 55 .60  10 -12

   0 + 1.327  2.327

PRECAUTIONS AND SOURCES OF ERROR

1. The connecting leads internal capacitance through compensated by Zero Setting, but
still could introduce some error.
2. Presence of vapour over the surface of the liquid.

REFERENCE

1. Principles of Electricity, L. Page and N.I. Adams, S. Chand & Co.(1955).

2. Classical Electricity and Magnetism, W.K.H. Panofsky and M. Phillips, Adison-
Wesley (1962).
3. Fundamentals of Electromagnetics, M.A. Wazed Miah, Tata McGraw-Hill (1982).

SES Instruments Pvt. Ltd. DSL-01 Page 12

 TECHNICAL SUPPORT

Feed Back

If you have any comments or suggestions about this product or this manual please let us know.
SES Instruments Pvt. Ltd. appreciates any customer feedback. Your input helps us evaluate and
improve our product.

To reach SES Instruments Pvt. Ltd.

* Phone : +91-1332-272852, 277118

* Fax : +91-1332 - 277118
* e-mail : info@sestechno.com; sestechno.india@gmail.com

Contacting for Technical Support

Before you call the SES Instruments Pvt. Ltd. Technical Support staff it would be helpful to
prepare the following information:

 If you problem is with the SES Instruments Pvt. Ltd apparatus, note :
o Model number and S. No (usually listed on the label at the backside of instrument).
o Approximate age of the apparatus.
o A detailed description of the problem/ sequences of events may please be sent by
email or Fax.

 If your problem relates to the instruction manual, note;

Model number and Revision (listed by month and year on the front cover).
Have the manual at hand to discuss your questions.

SES Instruments Pvt. Ltd. DSL-01 Page 13