Oms 420 User Manual Analizor Oxigen
Oms 420 User Manual Analizor Oxigen
Oms 420 User Manual Analizor Oxigen
OMS 420
MRU GmbH
OMS 420
INTRODUCTION
Thank you for purchasing the MRU OMS420 In-Situ oxygen and combustibles (O2nd COe monitoring probe.
Please read this instruction manual carefully before attempting to operate the analyzer. After you have become familiar
with this manual, move on to installation, operation and maintenance of the analyzer. Incorrect use of the analyzer could
cause an accident or injury.
Product development and improvement are dynamic goals of MRU, and specifications of this analyzer are subject to change
without prior notice.
Modification of this analyzer is strictly prohibited unless written approval is obtained from the manufacturer. MRU will not
be responsible for any issues of any kind resulting from any modification made to the analyzer without written permission.
It is important that this manual remains in the custody of the actual operator of the analyzer.
After reading the manual carefully, it should be stored in a safe, but accessible place.
This instruction manual should be delivered to the end user immediately upon delivery.
NOTICE:
It is prohibited to transfer part or all of this manual in written format without MRU written permission
Product development and improvement are dynamic goals of MRU, and descriptions and illustrations of the analyzer used
herein are subject to change without prior notice.
Shipping damage
Please inspect shipment for damage immediately upon receipt and in the presence of the carriers agent, and
note any visible damage on the shipping documents prior to signing. Report all damage to MRU within 3 days of
receipt of goods.
MRU GmbH
OMS 420
The products described in this manual are subject to continuous development and improvement and it is therefore acknowledged that this manual may contain errors or omissions. MRU encourages customer feedback and welcomes any
comments or suggestions relating to the product or documentation.
Please forward all comments or suggestions to the Customer Service Department at the following address:
MRU GmbH
Fuchshalde 8
74172 Neckarsulm / Obereisesheim
GERMANY
Phone: +49 71 32 99 62 0
Phone: +49 71 32 99 62 61 (Service)
Fax : +49 71 32 99 62 20
Email: info@mru.de
Homepage: www.mru.eu
This manual is intended solely as a guide to the use of the product.
MRU shall not be liable for any loss or damage whatsoever arising from content errors or misinterpretation of information from this
manual or any misuse resulting from the use of this manual.
MRU GmbH
OMS 420
Content:
Safety
10
11
4.1
Optimizing combustion.............................................................................................................11
4.2
OMS420 features......................................................................................................................12
4.3
Probe models............................................................................................................................13
4.3.1 Compact model OMS420 .............................................................................................13
4.3.2 Remote transmitter model OMS420RT.........................................................................14
4.3.3 High temperature model OMS420HT............................................................................15
4.3.4 Hazardous area model OMS420EX...............................................................................16
4.4
4.5
4.6
4.7
20
Operation
21
6.1
Start-up ....................................................................................................................................21
6.2
Warm-up ..................................................................................................................................21
6.3
6.4
6.5
6.6
Settings menu...........................................................................................................................24
6.6.1 PIN code level 1............................................................................................................24
6.6.2 Set analog output.........................................................................................................25
6.6.3 Damping.......................................................................................................................25
6.6.4 Back-purge setup .........................................................................................................25
6.6.5 Interval auto-calibration...............................................................................................26
6.6.6 Set calibration cylinder values ......................................................................................26
6.6.7 Set temperature measuring unit...................................................................................26
6.6.8 Set gas humidity...........................................................................................................26
6.6.9 Solenoid test ................................................................................................................27
6.6.10 OMS420 settings..........................................................................................................27
6.6.11 Reset to (factory) defaults ............................................................................................28
6.7
Calibration................................................................................................................................29
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MRU GmbH
OMS 420
6.7.1
6.7.2
6.7.3
6.7.4
6.7.5
6.7.6
6.7.7
6.7.8
6.7.9
6.7.10
6.7.11
Troubleshooting
38
Probe construction
39
8.1
8.2
8.3
8.4
50
8.5
8.6
58
MRU GmbH
OMS 420
10 Mounting flange
59
11 Maintenance
62
63
13 Firmware update
65
14 Technical specifications
68
15 Wiring schematics
69
75
17 Appendix
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MRU GmbH
OMS 420
Safety
The O2 probe may only be used in original, undamaged condition and in accordance with the operation manual.
All individuals dealing with the installation, commissioning, operation and maintenance of the analyzer or probe must be
qualified to do so and must strictly observe this operation manual.
Unauthorized modifications to any part of the analyzer or probe can create safety risks and are not permitted.
Power other than that specified in this manual must never be provided to the probe.
The probe shall not be used in under-stoichiometric combustion conditions, due to the possible presence of flammable
gases, eventually over the LEL (low explosion level).
Power must always be provided to the probe, even during boiler shut-down, to prevent the formation of condensate
which can damage the sensors.
Do not use the probe for any purpose other than that specified in this manual.
Exposure to corrosive gases such as silicone vapor, alkaline and heavy metals, P, Pb, high SO2, etc. will shorten the life
time of the sensors.
Use in hazardous areas zone 2 (class 1 div 2) requires additional hardware, available upon request.
It is mandatory to the user to insure that all persons operating this equipment are properly trained in
its operation and fully understand the operating principals of the equipment.
MRU GmbH, its affiliates and agents cannot be held responsible in any way for damage or injuries resulting from improper use, misuse or neglect in operating this equipment.
Caution
Probes installed inside flue ducts and stacks operate at elevated temperatures (often 1.000o F
and higher) create danger of serious skin burns to operators if proper handling precautions
and extreme care are not taken.
MRU GmbH
OMS 420
Heated zirconium oxide (ZrO2) is used as a ceramic solid electrolyte that is a good oxygen ion conductor at temperatures of approximately 1.550 o F (850 C), generated by an internal low power (20 W) heater element. The heater element is a PTC type, selfregulating device that does not require a thermocouple for temperature regulation. Constant sensor temperature is maintained by
controlling the heater voltage and current to fixed resistance of the heater element.
The electro-motive force (emf ) that is generated across the solid electrolyte by the presence of oxygen ions can be measured as a
sensor voltage (according to Nernst law).
where:
U0
zirconium temperature
Faraday constant
PO2ref
PO2sample =
This voltage is measured by micro-controller based transmitter electronics and converted into a standard 4 20 mA signal, linearized for oxygen in the range of 0 25 %.
The expected lifetime of this sensor is about 5 years + under normal operating conditions, and is not dependent on fuel type, but:
CAUTION:
If combustible gas (CO, H2, HC) in high concentrations are present in the sample gas, erroneous O2 readings will result due to local combustion at the sensors hot surface.
Exposure to corrosive gases (silicone vapor, alkaline and heavy metals, P, Pb, high SO2, etc.) will shorten the life of
the sensor.
Condensation of flue gas moisture close to the sensors flange must be prevented.
MRU GmbH
OMS 420
A solid ceramic electrolyte with thin-layer technology is used to measure the combustible gases (CxHy equivalent CO2). The ceramic electrolyte is a good oxygen ion conductor at temperatures of approximately 1.300 o F (700 C) generated by an internal, low
power (10 W) self regulating heater element.
The heated electrolyte has an initial voltage (U0 approximately zero mV) in the absence of combustible gases (H2, CO or CH4 or
C3H8, etc). In presence of these gases, the output voltage increases (see chart below) as these gases are oxidized at the hot surface
of sensor
The cell voltage is measured by micro-controller based transmitter electronics and converted into a standard, linearized 4 20 mA
signal for combustibles equivalent carbon monoxide (COe) in the range of approximate 0 1000 ppm.
Since the sensor is reacting to the presence of any combustible gas, but calibrated with CO+H2, equivalent CO measurements will
be reported.
The expected lifetime of this sensor is about 5 years + under normal operating conditions, and is not dependent on fuel type, but:
CAUTION:
Exposure to corrosive gases (silicone vapor, alkaline and heavy metals, P, Pb, high SO2, etc.)
will shorten the life of the sensor.
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MRU GmbH
OMS 420
The OMS420 is used to continuously measure oxygen and combustible gas concentrations in flue and stacks of industrial boilers or
furnaces, and those measurements are used to finely tune the combustion process.
4.1
Optimizing combustion
Optimum combustion conditions are achieved by decreasing the amount of excess air in the stack gas to the point where combustibles start to increase. See combustion diagram below:
The absolute value of combustibles in the stack gas of a burner depends very much on the design and construction of the
burner/boiler. Combustibles (CxHy) are lower in a well-designed system than they are one that is poorly designed.
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MRU GmbH
OMS 420
It is important to monitor the rising level of combustibles, labeled opt in the above diagram, and to trim the air/fuel ratio of the
burner to compensate for changing ambient conditions (pressure and humidity) and maintain the point of maximum heat efficiency.
The diagram below illustrates the burner operating under two conditions:
Conventional operation with increased safety margin (higher O2 concentration in the stack
gas).
Improved operation with optimized combustion (lowest O2 concentration in the stack gas
without a corresponding increase in combustibles).
The difference between the yellow area and the brown area represents the degree of combustion optimization, which in turn
represents savings in fuel.
OMS420 features
4.2
True wet gas analysis and calculation of dry oxygen level if humidity of gas is known.
Fast, safe and easy servicing by a single technician without removing the probe from the stack
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MRU GmbH
OMS 420
Probe models
4.3
This model shall be used at site with low heat radiated from the process (ambient temperature to transmitter electronics is less then 130 F / 55 C).
probe with flow guidance tube and flange (ANSI150 or DN80 or DN65)
back purge system (option) for high dust conditions only for site with flying ash type of dust
For higher temperature, less then 2.000 oF (1.200 oC), but higher then 1.200 F (650 C), the model OMS420RT with alloy AISI300
steel is recommended.
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MRU GmbH
4.3.2
OMS 420
This model shall be used when radiated heat from the process (duct, stack etc) will cause rising of ambient temperature higher
then 130 F (+55 C)
probe with flow guidance tube and flange (ANSI150 or DN80 or DN65)
-
back purge system (option) for high dust conditions only for site with flying ash type of dust
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MRU GmbH
4.3.3
OMS 420
This model shall be used at sites with clean and high temperature flue gas, less then 3.100 F (1.700 C)
probe with ceramic tube, ejector and flange (ANSI150 or DN80 or DN65)
The main differences between the remote transmitter model and the high temperature models are:
the use of ceramic tube of sampling probe on the high temperature model
the use of an ejector (air jet pump) to draw sample to the sensors..
When the ejector is purging instrument air with some 300 l/ h, a negative pressure on the back-side of a nozzle will be created. The
negative pressure draws the sample gas from the tip of ceramic tube to the sensors.
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MRU GmbH
4.3.4
OMS 420
This model shall be used at hazardous area sites classified as zone 2 (class 1, div 2)
Pressure reducer
Flushing valve
Safety vent
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MRU GmbH
4.4
OMS 420
The construction of the sampling probe is using the flow guidance principle
The tube is divided in half by a metal plate welded into the middle of the tube.
The probe is mounted on the stack by means of an 8-hole flange (ANSI 4, 150 lbs or DN100). The tip of the divider plate is oriented facing towards the flow, which directs the stack gas into and through the tube at the same velocity as the flow in the stack.
The detector body is mounted on the flanged side of the tube through a hole in the flange cut for that purpose. In the body, behind
a sintered metal filter (the measuring side of detector), the two sensors for oxygen and combustibles are exposed to the stack gas
flowing through the filter. In the detector behind the sensors, ambient air for reference gas diffuses through another sintered filter
(for dust protection) and flushes the backside of sensors (the reference side of the detector).
The flange feeds compressed air to several holes placed strategically around the detector and through a small tube, with airreleasing orifices spaced along its entire length, which is mounted along the metal plate in the center of the probe. The timing,
duration and number of pulses of compressed air is controlled by user-settable electronic parameters and released by a solenoid
valve. During purging, compressed air blows across the sintered metal filer protecting the sensors, and from the holes in the tiny
blow-back tube in the center of the probe, dislodging any accumulation of particulates so they will flow freely out of the probe and
back into the stack.
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MRU GmbH
OMS 420
Transmitter electronics
4.5
MRU GmbH
OMS 420
Manual calibration
calibration
4.6
To perform calibration of the instrument, the user can use following schematic diagram (or similar).
It is required to use moistured calibration gas (see 4.7) and two hand-ball valves to select between instrument air (zero gas) and
calibration gas (span gas) supply to calibration inlet port of unit.
manual calibration
Recommended calibration
calibration gas
4.7
For automatic calibration or manual calibration (see procedure in chapter 6.7.3) customer shall use following calibration gases:
1)
2)
Note: It is highly recommended to use water bubblier to moisture the calibration gas!!!
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MRU GmbH
OMS 420
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MRU GmbH
OMS 420
Operation
6.1
StartStart - up
Prior to start-up, use the following check list to verify that all conditions are set for proper start-up:
Checklist transmitter
Transmitter removed from the probe? (Note: always power up with transmitter removed from the probe/stack!!)
Ambient temperature around transmitter electronics in operating range of 0 F to 130 F (-20C to 55 C)?
Correct location of transmission cable (not in close proximity to high power supply cables or engines)?
Start up considerations:
Wiring:
Most problems are due to incorrect wiring. Please double check the wiring.
Shield should be grounded only at one side of the cable.
Leaks:
Insulation:
Check that the mounting flange has been properly insulated to prevent gas condensation.
Temperature:
Check mounting flange temperature: min. 160 F (70 C) and max. 300 F (150 C).
Check ambient temperature of transmitter for max. 130 F (+55 C).
Note:
If flange temperature at site with mounted probe and transmitter is below 160 F
(70 C) it is necessary to use a flange heater (ask MRU) to prevent condensation!!!
After power is switched on, the MRU logo and model of the unit will be displayed!
6.2
WarmWarm- up
Warm-up menu:
LCD will display a time count down for 30 minutes.
During warm-up, some inside measured values (heaters current and voltages) will be compared with credible thresholds and in
case of out-of-range, an error message will be displayed. After countdown, if everything is OK, the message will change from
please wait to the main measuring menu.
The SKIP function is used only for service purposes, to allow the operator to access other unit functions without waiting until the
end of warm-up interval time. During this time, measurement values are not credible.
During warm-up, all other menus (info, service and setting) are accessible.
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MRU GmbH
OMS 420
6.3
After warm-up, the unit will start automatically by displaying the main measurement menu.
O2 real time value with 0.01% resolution
COe real time value with ppm resolution
NOTE:
If between 30 min no button is
pressed during the measurement,
the level will be set on "0". I.e. the
menus SET and CALIB are only by
renewed PIN input usable.
Info menu
6.4
In the INFO menu the following parameters can be called up from a scroll up/down list:
Next back-purge
in hours/minutes
If the display shows ---- the automatic set to zero is not activated
Gas humidity
display in % 1 - 25 or disabled
O2 value
wet:
The O2 display is calculated to wet (*)
dry:
The O2 display is calculated to dry(*).
The gas humidity can be set by SET to Set gas humidity
4 - 20 mA 02
4 - 20 mA CO
Firmware
Hardware
Serial number
O2 sensor
installed
CO sensor
installed/not installed
O 2 max = 20.97%
oxygen content in air
O2 wet = measured O2-value in wet stack gas
O2dry = calculated (%) O2-value dry
100
100 H
22
O 2 wet
H = 100 1
O 2dry
MRU GmbH
6.5
OMS 420
Service menu
Displays actual 6 lines from a scroll up/down list with measured (A/D converter) components information.
Press the UP or DOWN key and return back to main measuring menu by pressing BACK.
standard value
allowed deviation
O2 cell
O2 heater
O2 heater
0,3 A
CO cell
10 mV
CO heater
-3,0 V. + 1 V
CO heater
Unit temperature
5 mV
2V
0,1 A
less then 160 F (70 C)
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MRU GmbH
6.6
OMS 420
Settings menu
This menu is protected by a user level 1 PIN code. Changing the pin code is described in following chapter.
6.6.1
Entering the factory default PIN code 1111 (user level 1), gains access to the SET main menu and the above settings.
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MRU GmbH
6.6.2
OMS 420
PREV or NEXT
EDIT
OK
BACK
20mA: O2
20mA: CO
Hold after purge
0 21.00 %
0 1.000 ppm
typical 20 sec. (from 5 to max 200 seconds)
Notice: The last measured value on analog output 4-20mA after back-purge is hold even after back-purge cycle is finished.
6.6.3
Damping
This function allows user to set a damping (averaging the measurement over a period of time) of measurement, in the display as
well in the analog output.
PREV or NEXT
EDIT
OK
BACK
Integration times from 0 to 30 seconds are settable, where 0 seconds means no damping.
6.6.4
Back-purge setup
This function allows setup of the optional back-purge solenoid valve to control:
PREV or NEXT
EDIT
OK
BACK
pulse duration or interval time for energizing the solenoid valve (opening the valve)
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MRU GmbH
6.6.5
OMS 420
Interval auto-calibration
PREV or NEXT
EDIT
BACK
6.6.6
This function allows setting the values of span gas cylinders used for calibration.
PREV or NEXT
EDIT
OK
BACK
The set values for zero are fixed values, programmed into the units firmware.
The values for the calibration gas cylinder setting have to be set to the correct cylinder values for both O2 and CO.
6.6.7
EDIT
OK
BACK
This function allows setting the value of gas humidity (if known) and selection of either wet oxygen measurement or dry oxygen
calculation.
NEXT
EDIT
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MRU GmbH
OK
BACK
OMS 420
save values
return to main menu
Solenoid test
With the menu option "Solenoid test" allows to test each individual solenoid valve (if installed)
LCD Contrast
0-20
Device-ID (Modbus)
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MRU GmbH
OMS 420
YES
NO
Factory defaults
Auto-calibration
OFF
Back-purge
OFF
4 20 mA Range O2
20,96 %
4 20 mA range CO
1.000 ppm
O2 cylinder1
21,00 %
O2 cylinder2
2,00 %
CO cylinder1
0 ppm
CO cylinder2
Pulse duration
2 sec.
Numb. of pulses
20 sec.
Unit temp.
Display O2
wet
Humidity
--.- %
(without)
Interval (days)
Auto-Cal.
AIR
(autocalibration = OFF)
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MRU GmbH
6.7
OMS 420
Calibration
The transmitter should be powered up for at least one hour before calibration.
A test (calibration) gas cylinder is connected to the calibration gas inlet port for calibration.
Adjustment can be done manually or automatically using the solenoid valves of the optional pneumatic unit.
manual calibration
The test gas (clean fresh air/instrument air or calibration gas) flows through the hole inside the small flange (sensor manifold), purges the sensors and exits through the sintered metal filter to the inside probe tube mounted on the stack.
On site calibration is done without removing the probe from the stack.
After calibration, tighten the calibration inlet port plug with a 14 mm wrench for 1/6 of a turn.
Perform adjustment:
1
Purge sensor with ambient air (min 40 l/h, max. 60 l/h using the calibration gas inlet port).
When being purged with fresh air, the analog output signal should be 17.37 mA (for 0 25 % O2 measuring range).
With calibration gas (2% O2 in N2), the analog output should be 5.28mA (for 0 - 25% O2 measuring range).
MRU GmbH
6.7.1
OMS 420
Calibration with AIR (zero gas) or GAS (span gas) requires the use of level 2 pin code
POS
UP / DOWN
6.7.2
position
to change the numbers
If there is no calibration gas available and the cell must be replaced, this function permits changing a cell without calibration. This
can only be done if the cell factors have been measured at MRU and delivered together with the spare sensor.
PREV or NEXT
EDIT
OK
BACK
1)
move cursor
change value by means of UP/DOWN and POS
save values
return to calibration menu
O2 cell setup requires input (edit function) of O2 factor and O2 offset values delivered with the spare sensor
2)
Temperature compensation of 20.9 % O2 is required when oxygen value at air is changed too much because of gas or
flange temperature change. The difference of air oxygen measurement at lower temperature to measurement at higher temperature will be edit as Temp.offs value.
NOTE:
This procedure should be followed by new calibration using calibration gas cylinder.
Only authorized persons or manufacturers trained technicians are authorized to perform adjustments on the OMS420.
6.7.3
If there is no calibration gas available and the cell must be replaced, this function permits changing a cell without calibration. This
can only be done if the cell factors have been measured at MRU and delivered together with the spare sensor.
PREV or NEXT
EDIT
OK
BACK
move cursor
change value by means of UP/DOWN and POS
save values
return to calibration menu
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MRU GmbH
OMS 420
CO cell setup factor and CO offset setup factor will be edit using the values delivered together with the spare sensor.
Set point of heat resistor [Ohm] must be also carried out according to 6.7.12
NOTE:
This procedure should be followed by new calibration using calibration gas cylinder.
Only authorized persons or manufacturers trained staff are allowed to perform adjustments on the OMS420!
6.7.4
PREV or NEXT
EDIT
OK
BACK
move cursor
change value by means of UP/DOWN and POS
save values
return to calibration menu
and
If actual values displayed are other than -10mV to +100mV setting can be adjusted by selecting Set offset or Set span and
editing and replacing the displayed numbers with the actual numbers.
Factory default = factory adjusted values
ATTENTION:
Changes of these factors require new gas calibration.
Only authorized persons or manufacturers trained technicians are authorized to perform adjustments on the OMS420.
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MRU GmbH
6.7.5
OMS 420
Connect precision 100 Ohm resistor (0.1% tolerance) to both analog outputs of O2 and CO measurements.
Measure the voltage across the resistors using a precision digital multi-meter.
PREV or NEXT
EDIT
OK
BACK
move cursor
change value by means of UP/DOWN, until you read 400mV, up to2000mV on the multi-meter
save values
return to calibration menu
Note:
The 4 20mA analog output factory adjustment can deteriorate over time, so measured values must be verified occasionally.
Only authorized persons or manufacturers trained staff are allowed to perform adjustments on the OMS420.
COe measurement
O2 measurement
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MRU GmbH
6.7.6
OMS 420
Calibration AIR
This menu performs the 1 point calibration with AIR (zero gas).
Wait approximately 5 minutes while instrument air is being supplied to sensors to allow signals to stabilize.
Press CALIB key
O2 OK. CO OK
or
O2 failed! CO failed!
6.7.7
This menu performs the 2 points calibration with combined AIR and GAS (zero gas and span gas).
For the calibration, the use of moistured mixture gas (O2, CO and H2 ) is mandatory.
Moisturing the span gas requires the use of water bubblier!
With single component gas CO the calibration is not possible.
If no mixture gas is available, then see chapter 6.7.8.
Calibration of O2 only: set CO cylinder (value) = 0
Calibration of CO only: set O2 cylinder (value) = 0
no calibration
no calibration
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MRU GmbH
OMS 420
Wait approximately 5 minutes while instrument air is being supplied
to sensors to allow signals to stabilize.
Press CALIB key
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MRU GmbH
6.7.8
OMS 420
CO correction factor
This function allows user to perform site calibration of combustibles measurement with a comparative selective CO measurement,
using portable CO analyzer (e.g. Delta65). This will make the equivalency to CO and is recommended to be carried out at stable, constant combustion process.
Because sensor is measuring all combustibles in the flue gas, a difference to selective CO measurement will occur.
By using the correction factor, this difference will be minimized, the instrument will display same value as the comparing CO selective measuring instrument.
1) The measured value by means of Delta65 can be set (desired value) by pressing EDIT key.
2) Using theUP and DOWN keys will change this value until it corresponds to Delta65 measurement of CO.
3) Then press OK key to correct the combustibles measurement to selective CO measured value.
NOTE: by pressing the key FACT. the CO correction factor will be set to 1000 (amplification is 1)!!!!
In that case, adjustment of COe reading according to measurement by means of Delta65 is out of order!
Use a portable analyzer to measure CO in the flue gas and to adjust accordingly the desired value.
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MRU GmbH
6.7.9
OMS 420
PREV or NEXT
EDIT
OK
BACK
move cursor
change value by means of UP/DOWN and POS
save values
return to calibration menu
ATTENTION:
Changes of these parameters require new calibration.
Only authorized persons or manufacturers trained technicians are authorized to perform adjustments on the OMS420
6.7.10 CO heat resistor regulation (factory only)
PREV or NEXT
EDIT
OK
BACK
move cursor
change value by means of UP/DOWN and POS
save values
return to calibration menu
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OMS 420
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MRU GmbH
OMS 420
Troubleshooting
If the system detects an error, the plain text will be displayed after pressing the Error key in the service menu.
Malfunction:
Corrective action:
No display
Display:
Heating current<0.5A
Replace sensor
Display:
Configuration not ok
Checksum wrong
Display:
Flash error!
Display:
Unit to warm
Hot environment
Transmitter does not react with sample gas
from stack
Calibration error
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MRU GmbH
Probe construction
8.1
Compact
Compact probe OMS420 with ANSI flange
8.1.1
OMS 420
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MRU GmbH
8.1.2
OMS 420
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MRU GmbH
8.1.3
OMS 420
POS.
BESCHREIBUNG
DESCRIPTION
61229
61229A
61229B
61229C
61229D
61229E
61229H
61229M
61494
1x
61538
8x
61537
8x
Federringe, M18
61536
8x
61153
8x
61398
1x
61391
1x
Sintermetallfilter
61227
1x
Dichtung
seal gasket
10
61228
1x
Adapterflansch
adapter flange
11
61396
4x
12
61390
1x
CO-Sensor
CO-sensor
13
61939
1x
Einschraubverschraubung
14
59528
1x
O2-Sensor
ZrO2-sensor
15
55106
1x
Dichtung 1/8
16
55105
1x
Einschraubverschraubung
screw-in fitting
17
56912
1x
Blindstopfen
locking plug
18
54519
1x
Sttzhlse
carrying bracket
19
50624
PTFE-hose, 6/4 mm
20
61389
2x
Dichtung
seal gasket
21
61397
4x
22
61230
1x
Montagerohr
mounting tube
23
59447
1x
Sintermetallfilter, 18x2
24
59449
1x
Sicherungsring, 18x1
25
61392
1x
Gehuse
enclosure
26
61393
1x
Tastaturfolie
keypad
27
61411
1x
Display
display
28
61293A
1x
Platine, komplett
54
61295A
1x
27/28
61292
1x
29
61407
1x
Stifteinsatz
pin holder
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MRU GmbH
OMS 420
30
61409
1x
Anbaugehuse
connector housing
31
61408
1x
Buchseneinsatz
socket holder
32
61410
1x
Tllengehuse
connector housing
33
61159
1x
34
61234
1x
Kabelverschraubung
1.1
61947
2x
Kupfer-Dichtring
1.2
61533
2x
Verschluschraube G
joint union G
61489
1x
plug nipple
61399
1x
Magnetventil
solenoid valve
61868
2x
Einschraubverschraubung
screw-in fitting
61867
1x
61400
1x
Anschlussstecker
Plug connector
60892
61869
8.1.4
1x
POS.
BESCHREIBUNG
DESCRIPTION
61494
1x
61391
1x
Sintermetallfilter
61227
1x
Dichtung
seal gasket
12
61390
1x
CO-Sensor
CO-sensor
14
59528
1x
O2-Sensor
ZrO2-sensor
20
61389
2x
Dichtung
seal gasket
23
59447
1x
Sintermetallfilter, 18x2
24
59449
1x
Sicherungsring, 18x1
26
61393
1x
Tastaturfolie
keypad
61399
1x
Magnetventil
42
MRU GmbH
8.2
8.2.1
OMS 420
43
MRU GmbH
8.2.2
OMS 420
44
MRU GmbH
8.2.3
OMS 420
POS.
BESCHREIBUNG
DESCRIPTION
62390
62390A
62390B
62390C
62390D
62391
62391A
62391B
62391C
62391D
52556
1x
56851
4x
56850
4x
Federringe, M12
56849
4x
62394
4x
61398
1x
61391
1x
Sintermetallfilter
61227
1x
Dichtung
seal gasket
10
61228
1x
Adapterflansch
adapter flange
11
61396
4x
12
61390
1x
CO-Sensor
CO-sensor
13
61939
1x
Einschraubverschraubung
14
59528
1x
O2-Sensor
ZrO2-sensor
15
55106
1x
Dichtung 1/8
16
55105
1x
Einschraubverschraubung
screw-in fitting
17
56912
1x
Blindstopfen
locking plug
18
54519
1x
Sttzhlse
carrying bracket
19
50624
PTFE-hose, 6/4 mm
20
61389
2x
Dichtung
seal gasket
21
61397
4x
22
61230
1x
Montagerohr
mounting tube
23
59447
1x
Sintermetallfilter, 18x2
24
59449
1x
Sicherungsring, 18x1
25
61392
1x
Gehuse
enclosure
26
61393
1x
Tastaturfolie
keypad
27
61411
1x
Display
display
28
61293A
1x
Platine, komplett
54
61295A
1x
45
MRU GmbH
OMS 420
27/28
61292
1x
29
61407
1x
Stifteinsatz
pin holder
30
61409
1x
Anbaugehuse
connector housing
31
61408
1x
Buchseneinsatz
socket holder
32
61410
1x
Tllengehuse
connector housing
33
61159
1x
34
61234
1x
Kabelverschraubung
1.1
61947
2x
Kupfer-Dichtring
1.2
61533
2x
Verschluschraube G
joint union G
61489
1x
plug nipple
61399
1x
Magnetventil
solenoid valve
61868
2x
Einschraubverschraubung
screw-in fitting
61867
1x
61400
1x
Anschlussstecker
Plug connector
60892
61869
8.2.4
1x
POS.
BESCHREIBUNG
DESCRIPTION
61494
1x
61391
1x
Sintermetallfilter
61227
1x
Dichtung
seal gasket
12
61390
1x
CO-Sensor
CO-sensor
14
59528
1x
O2-Sensor
ZrO2-sensor
20
61389
2x
Dichtung
seal gasket
23
59447
1x
Sintermetallfilter, 18x2
24
59449
1x
Sicherungsring, 18x1
26
61393
1x
Tastaturfolie
keypad
61399
1x
Magnetventil
46
MRU GmbH
OMS 420
8.3
8.3.1
47
MRU GmbH
8.3.2
OMS 420
48
MRU GmbH
8.3.3
OMS 420
POS.
BESCHREIBUNG
DESCRIPTION
61229
61229A
61229B
61229C
61229D
61229E
61229H
61229M
61494
1x
61538
8x
61537
8x
Federringe, M18
61536
8x
61153
8x
61398
1x
61391
1x
Sintermetallfilter
61227
1x
Dichtung
seal gasket
10
61228
1x
Adapterflansch
adapter flange
11
61396
4x
12
61390
1x
CO-Sensor
CO-sensor
13
61939
1x
Einschraubverschraubung
14
59528
1x
O2-Sensor
ZrO2-sensor
15
55106
1x
Dichtung 1/8
16
55105
1x
Einschraubverschraubung
screw-in fitting
17
56912
1x
Blindstopfen
locking plug
18
54519
1x
Sttzhlse
carrying bracket
19
50624
PTFE-hose, 6/4 mm
20
61389
2x
Dichtung
seal gasket
21
61397
4x
22
61230
1x
Montagerohr
mounting tube
23
59447
1x
Sintermetallfilter, 18x2
24
59449
1x
Sicherungsring, 18x1
25
61392
1x
Gehuse
enclosure
26
61393
1x
Tastaturfolie
keypad
27
61411
1x
Display
display
28
61293A
1x
Platine, komplett
27/28
61292
1x
54
61295A
1x
29
61407
1x
Stifteinsatz
pin holder
30
61409
1x
Anbaugehuse
connector housing
49
MRU GmbH
OMS 420
31
61408
1x
Buchseneinsatz
socket holder
32
61410
1x
Tllengehuse
connector housing
34
61234
1x
Kabelverschraubung
35
61985
1x
Gehuse (Klemmkasten)
36
56420
1x
Logo-Schild
logo plate
37
54068
1x
Hutschiene
38
50068
10 x
Klemme
clamp
39
50064
2x
Klemme
clamp
40
58929
1x
Kabelverschraubung PG9
41
61159
1x
42
61192
1x
Kabel lflex
cable lflex
43
61989
1x
Kabelstecker
cable connector
44
61990
1x
Flanschdose, 12 polig
45
59536
1x
Netzteil
power supply
1.1
61947
2x
Kupfer-Dichtring
1.2
61533
2x
Verschluschraube G
joint union G
61489
1x
plug nipple
61399
1x
Magnetventil
solenoid valve
61868
2x
Einschraubverschraubung
screw-in fitting
61867
1x
61400
1x
Anschlussstecker
Plug connector
60892
61869
8.3.4
1x
POS.
BESCHREIBUNG
DESCRIPTION
61494
1x
61391
1x
Sintermetallfilter
61227
1x
Dichtung
seal gasket
12
61390
1x
CO-Sensor
CO-sensor
14
59528
1x
O2-Sensor
ZrO2-sensor
20
61389
2x
Dichtung
seal gasket
23
59447
1x
Sintermetallfilter, 18x2
24
59449
1x
Sicherungsring, 18x1
26
61393
1x
Tastaturfolie
keypad
61399
1x
Magnetventil
45
59536
1x
Netzteil
power supply
8.4
50
MRU GmbH
OMS 420
8.5
8.5.1
51
MRU GmbH
8.5.2
OMS 420
52
MRU GmbH
8.5.3
OMS 420
POS.
BESCHREIBUNG
DESCRIPTION
62390
62390A
62390B
62390C
62390D
62391
62391A
62391B
62391C
62391D
52556
1x
56851
4x
56850
4x
Federringe, M12
56849
4x
62394
4x
61398
1x
61391
1x
Sintermetallfilter
61227
1x
Dichtung
seal gasket
10
61228
1x
Adapterflansch
adapter flange
11
61396
4x
12
61390
1x
CO-Sensor
CO-sensor
13
61939
1x
Einschraubverschraubung
14
59528
1x
O2-Sensor
ZrO2-sensor
15
55106
1x
Dichtung 1/8
16
55105
1x
Einschraubverschraubung
screw-in fitting
17
56912
1x
Blindstopfen
locking plug
18
54519
1x
Sttzhlse
carrying bracket
19
50624
PTFE-hose, 6/4 mm
20
61389
2x
Dichtung
seal gasket
21
61397
4x
22
61230
1x
Montagerohr
mounting tube
23
59447
1x
Sintermetallfilter, 18x2
24
59449
1x
Sicherungsring, 18x1
25
61392
1x
Gehuse
enclosure
26
61393
1x
Tastaturfolie
keypad
27
61411
1x
Display
display
28
61293A
1x
Platine, komplett
27/28
61292
1x
54
61295A
1x
53
MRU GmbH
OMS 420
29
61407
1x
Stifteinsatz
pin holder
30
61409
1x
Anbaugehuse
connector housing
31
61408
1x
Buchseneinsatz
socket holder
32
61410
1x
Tllengehuse
connector housing
34
61234
1x
Kabelverschraubung
35
61985
1x
Gehuse (Klemmkasten)
36
56420
1x
Logo-Schild
logo plate
37
54068
1x
Hutschiene
38
50068
10 x
Klemme
clamp
39
50064
2x
Klemme
clamp
40
58929
1x
Kabelverschraubung PG9
41
61159
1x
42
61192
1x
Kabel lflex
cable lflex
43
61989
1x
Kabelstecker
cable connector
44
61990
1x
Flanschdose, 12 polig
45
59536
1x
Netzteil
power supply
1.1
61947
2x
Kupfer-Dichtring
1.2
61533
2x
Verschluschraube G
joint union G
61489
1x
plug nipple
61399
1x
Magnetventil
solenoid valve
61868
2x
Einschraubverschraubung
screw-in fitting
61867
1x
61400
1x
Anschlussstecker
Plug connector
60892
61869
8.5.4
1x
POS.
BESCHREIBUNG
DESCRIPTION
61494
1x
61391
1x
Sintermetallfilter
61227
1x
Dichtung
seal gasket
12
61390
1x
CO-Sensor
CO-sensor
14
59528
1x
O2-Sensor
ZrO2-sensor
20
61389
2x
Dichtung
seal gasket
23
59447
1x
Sintermetallfilter, 18x2
24
59449
1x
Sicherungsring, 18x1
26
61393
1x
Tastaturfolie
keypad
61399
1x
Magnetventil
45
59536
1x
Netzteil
power supply
54
MRU GmbH
OMS 420
8.6
8.6.1
55
MRU GmbH
8.6.2
OMS 420
POS.
BESCHREIBUNG
DESCRIPTION
61494
1x
61538
8x
61537
8x
Federringe, M18
61536
8x
61153
8x
61398
1x
61391
1x
Sintermetallfilter
61227
1x
Dichtung
seal gasket
10
61228
1x
Adapterflansch
adapter flange
11
61396
4x
12
61390
1x
CO-Sensor
CO-sensor
13
61939
1x
Einschraubverschraubung
14
59528
1x
O2-Sensor
ZrO2-sensor
15
55106
1x
Dichtung 1/8
16
55105
1x
Einschraubverschraubung
screw-in fitting
17
56912
1x
Blindstopfen
locking plug
18
54519
1x
Sttzhlse
carrying bracket
19
50624
PTFE-hose, 6/4 mm
20
61389
2x
Dichtung
seal gasket
21
61397
4x
22
61230
1x
Montagerohr
mounting tube
23
59447
1x
Sintermetallfilter, 18x2
24
59449
1x
Sicherungsring, 18x1
25
61392
1x
Gehuse
enclosure
26
61393
1x
Tastaturfolie
keypad
27
61411
1x
Display
display
28
61293A
1x
Platine, komplett
27/28
61292
1x
54
61295A
1x
29
61407
1x
Stifteinsatz
pin holder
30
61409
1x
Anbaugehuse
connector housing
31
61408
1x
Buchseneinsatz
socket holder
32
61410
1x
Tllengehuse
connector housing
34
61234
1x
Kabelverschraubung
35
61985
1x
Gehuse (Klemmkasten)
36
56420
1x
Logo-Schild
logo plate
37
54068
1x
Hutschiene
38
50068
10 x
Klemme
clamp
39
50064
2x
Klemme
clamp
56
MRU GmbH
OMS 420
40
58929
1x
Kabelverschraubung PG9
41
61159
1x
42
61192
1x
Kabel lflex
cable lflex
43
61989
1x
Kabelstecker
cable connector
44
61990
1x
Flanschdose, 12 polig
45
59536
1x
Netzteil
power supply
46
62022
1x
47
62004
1x
Dichtung Halteflansch
48
62021
1x
Halteflansch
fixing flange
49
62084
3x
50
62083
1x
51
62023
1x
Dse
nozzle
52
54899
1x
Dichtung
seal gasket
53
59555A
1x
53
59555
!X
53
59555B
1x
53
56987
1x
Entnahmerohr,Kanthal, 1.000 mm
53
56987B
1x
Entnahmerohr,Kanthal, 1.500 mm
1.1
61947
2x
Kupfer-Dichtring
1.2
61533
2x
Verschluschraube G
joint union G
61489
1x
plug nipple
8.6.3
57
MRU GmbH
OMS 420
Temperature of stack gas and pressure must be within specifications of selected probe model
Ensure that space around the installation point is free of obstructions and there is adequate space to allow comfortable working access to the probe and electronics.
If the installation pint is elevated, ensure that an adequate platform providing safe and comfortable access to
the probe and electronics is in place. Ensure that there is adequate room to manipulate the full length of the
probe into position for the installation.
The use of a rain and sun shade mounted above the probe is recommended on outdoor installations.
To protect the analyzer from radiated heat from the stack (ambient temperature of transmitter higher than 130o
F (+55C), install a heat shield or use a Vortec cooler (optional item).
Verify that the temperature at the mounting flange will be approximately 140 to 300F (70 to 150C)
For high temperature stack gas use a longer tube-flange assembly (mounting flange, see drawing
chapter 10) which extends the electronics further from the stack wall.
For low temperature stack gas, the mounting flange must be thermally insulated, or an optional
heated flange must be used to avoid condensation.
Do not install the data transfer cable from the OMS420 to the control room inside cable conduit containing cable for other high power devices (large fan, motor, compressor, transformer, etc).
Attach transmitter OMS 420 to the probe flange only after adequate warm-up time!
Screw on the transmitter by means of 4x M6 screws using a 5mm hexagon. Verify a tight fit.
Note: Seal gasket must be replaced every time the transmitter is removed and replaced.
Before installing the probe refer to the drawings to determine the best mounting location and position, and the hardware requirements for your installation. The probe can be mounted vertically if required.
Cut a hole in the stack breeching where the probe is to be mounted. Verify that the diameter of the hole corresponding to pipeflange assembly dimensions.
Measure the thickness of the stack wall (through the hole) and add approximately 0.4 (10 mm).
Add thermal insulation equal to the thickness of the stack plus approximately 1 - 2 (40 - 50mm) to determine the length of the
mounting pipe.
Weld a carbon steel, raised or flat faced flange to the end of the pipe (see pipe/flange ANSI 15C assembly drawing below).
Insert the pipe/flange assembly into the hole until the pipe insert inside the stack is 0.4 (10 mm) or longer for long probes. Tilt the
pipe/flange assembly approx. 5 from horizontal to allow condensation to drain back into the stack.
Weld the pipe/flange assembly to the stack wall.
IMPORTANT: Make certain the probe is aligned property to the gas flow direction while mounting
the probe on the stack.
58
MRU GmbH
10
Mounting flange
10.1
OMS 420
The OMS420 probe is mounted to the stack using a mounting flange as illustrated in the drawing below
L1 = as short as possible for low stack gas temperatures (use additional thermal insulation for the flange)
L1= longer for higher stack gas temperatures
L2= L1 plus stack insulation depth
L3= inside stack tube, used to support the OMS 420 probe for probes longer than ~ 5 ft. (1500mm)
59
MRU GmbH
OMS 420
L1 = as short as possible for low stack gas temperatures (use additional thermal insulation for the flange)
L1= longer for higher stack gas temperatures
L2= L1 plus stack insulation depth
L3= inside stack tube, used to support the OMS 420 probe for probes longer than ~ 5 ft. (1500mm)
60
MRU GmbH
10.3
10.4
Mounting
Mounting vertical stack
OMS 420
61
MRU GmbH
11
OMS 420
Maintenance
Increasing response time indicates that the sintered
filter is getting clogged and cleaning is necessary.
Unscrew the transmitter by removing the
4 hexagonal screws using a 5 mm Allen key.
Remove the transmitter from the flange.
Clean the filter using an ultrasonic bath with adequate solvent for the type of dust (benzene for tar
etc) or any other effective method.
Replace the filter and the lock washer.
62
MRU GmbH
12
OMS 420
63
POS.
DESCRIPTION
Electrical connector
61869
3a
61293A
3a
LC Display
61411
3b
61295A
60892
O2 sensor
59528
COe ensor
61390
Adapter flange
61228
61153
Mounting tube
61230
10
61391
11
59447
12
61905
13
61939
62056
62057
14
61039
MRU GmbH
OMS 420
Remove the 8 wires from the sensors.(see picture below) (4 wires if the COe sensor is not installed) and from the OMS
PCB (3b).
O2 sensor
CO sensor
Unscrew 4 mounting screws (8) from the adapter flange (7) by using an allen key 5 mm
Screw the new zirconium sensor (5) out of the adapter flange (7).
COe sensor (6) is removed and replaced in the same manner.
Take out COe sensor (see arrow on illustration for unscrewing direction)
Change the COe sensor - dont forget new front and back ferrule - and fasten screw-in fitting (13)
Mount the tube (9) onto the flange using (8) screws
Plug the connector (1) and power supply into the transmitter
64
MRU GmbH
13
OMS 420
Firmware update
13.1 procedure
a) Connect Update-Cable between OMS 420 and PC (with RS485-Converter
b) Start PC-Program MRU-Uploader .
c) Select the RS232-COM port (COMx ).
d) Load the file by click on the "File"/"Load file" and select the new firmware file
(OMS420_1.02_28.04.08_English_B_Standard.mru)
One INFO message appears on the screen, but please do not press OKyet!
e) Disconnect power supply of OMS 420. While OMS420 is un-powered, press F1 key and power-on the
OMS420; then release pressing the F1 key.
OMS 420 is in theboot mode, display is shut-off.
Now you can press the "OK" button on the PC display.
f) Time for update with new firmware is usually some two minutes.
Do not press any key during this data transfer to OMS420!
After the update, analyzer will start automatically in the normal measuring mode.
13.2
USB s eria
erial adapter RS485 (USB(USB- COM_
COM_)
13.3
65
MRU GmbH
OMS 420
Note:
With RS485 the line ends must be provided with a terminal resistance. (jumper on 1-2)
13.4
66
MRU GmbH
13.5
OMS 420
Connection OMS420
OMS420 to USBUSB- COM_
COM_
Power supply to transmitter connector OMS420 (port 1 and port 6, see above) is necessary.
67
MRU GmbH
14
OMS 420
Technical specifications
Measurements
Measurement principle
Lifetime of cells
Warm-up time
minimum 30 minutes
Measurement range
0 25.0 % for O2
0 1,000 ppm for COe
Resolution
Repeatability
Linearity
Accuracy
O2:
Response time
< 10 seconds
Electronics
Output signals
2 x 4 20 mA, galvanic isolated, max. 500 R (for direct transfer to process PLC)
RS 485, galvanic isolated digital data transfer (Modbus protocol RTU)
Power supply
Ambient temperature
Ambient humidity
Protection
(*) in the absence of heavy metals, silicones, silicates, aggressive and/or corrosive gases
68
MRU GmbH
15
15.1
OMS 420
Wiring schematics
Terminal assignment of plugplug - in connector to transmitter
Electrical connector for power supply and data transfer
1. Unscrew A
2. Unscrew B
3. Unscrew C
(cord grip)
(PG 13,5)
(socket holder)
FG connection
PIN
Plug of transmitter
OMS 420
OMS 420-RT
Terminal connector
of pcb MAIN
PE
FG (frame grounding)
FG
X1-6
N 100240 Vac
X1-5
L 100...240 Vac
X1-4
2&3
RS 485 (in)
X2-16
7&8
RS 485 (out)
X2-16
4 20 mA + CO
X2-11
4 20 mA - CO
X2-10
4 20 mA + O2
X2-13
10
4 20 mA - O2
X2-12
69
MRU GmbH
15.2
OMS 420
70
MRU GmbH
15.3
OMS 420
71
MRU GmbH
15.4
OMS 420
72
MRU GmbH
15.5
OMS 420
73
MRU GmbH
15.6
OMS 420
Power supply
A DIN rail-power supply is also suitable if it delivers max 24dc voltage and is 90 - 100W power rated.
Make certain connection polarity is correct.
Use PIN 1 & 6 for the 24 V dc/100 W power supply.
74
MRU GmbH
OMS 420
16
The transmitter electronics control the pneumatic components of this device, and performs automatic calibrations as set by the
user.
Automatic calibration
The interval time between two calibrations, the type of calibration (single point or double point calibration) and the gas concentration of the calibration gas cylinder are all user settable.
At the set times, the transmitter energizes the solenoid valves, directing the calibration gases (instrument air as zero gas and calibration gas as span gas) to the probe calibration inlet port.
16.1
For automatic calibration or manual calibration (see procedure in chapter 6.7.3) customer shall use following calibration gases:
3)
4)
Note:
The calibration interval is selectable between 0 and 99 days, the purge time between 1 and 10 minutes and the kind of
calibration like 1 point (AIR) or 2 point (AIR/GAS) calibration.
0 days means auto-cal is not selected (disabled).
75
MRU GmbH
OMS 420
6x
The auto calibration also will start automatically after a power shutt-down (if setup).
76
MRU GmbH
OMS 420
16.3 Error
Error detection
If calibration fails, an error message will be displayed.
or
or
or
or
77
MRU GmbH
16.4
OMS 420
PU420 construction
POS.
BESCHREIBUNG
DESCRIPTION
62132
OMS 420RT-PU
OMS 420RT-PU
62123
2x
Kabel, lflex100
cable, lflex100
61869
2x
Verschraubung PG 7
screw-in fitting
60169
1x
Durchflussmesser
flow meter
56587
1x
T-Stck TS 3
T-fitting TS 3
60182
4x
Verschraubung PVDF
60889
2x
Anschlussstecker Magnetventil
62112
2x
Magnetventil
solenoid valve
55105
2x
Einschraubverschraubung
10
55106
2x
Dichtung 1/8
11
61116
1x
Schottverschraubung
screw-in fitting
12
55641
8x
Vitonschlauch
Viton hose
78
MRU GmbH
16.5
OMS 420
79
MRU GmbH
OMS 420
17
Appendix
17.1
Error codes
02
04
Flash Error, new adjustment required Please contact your dealer (manufacturer).
08
01
32
64
128
At the same time if several errors line up, then the error codes are to be added.
Her one example:
33
80
MRU GmbH
OMS 420
81