Detcon Model DM Transmitter Test Fixture
Operators Instruction Manual
October 22, 2007 * Document 3391 * Revision 1.0
DETCON, Inc.
3200 Research Forest Dr., Building A-1
The Woodlands, Texas 77387
Ph. 713-559-9200 / Fax 281-298-2868
www.detcon.com
Detcon Model DM Transmitter Test Fixture
Table of Contents
1.0 Description
2.0 Features
3.0 Specifications
4.0 Operation
5.0 Test Fixture Calibration
6.0 Warranty
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Detcon Model DM Transmitter Test Fixture
1.0 Description
The Detcon Model DM Transmitter Test Fixture is designed to test the operation of
Detcon Model DM Series H2S Transmitters. Models covered are series DM-5xx, DM550x, and DM-6xx.
NOTE: Model series DM-4xx loop powered transmitters are not compatible with this test
fixture.
2.0 Features
Reference figure 1 below for feature locations.
1 - Internal power supply and power switch
2 - Plug-in connector for DM-5xx transmitters
3 - mA output digital LED meter
4 - Plug-in connector for DM-550 and DM-6xx transmitters
5 - RS-485 output (DM-550 and DM-6xx)
6 - Fault and alarm relay output LEDs (DM-550 and DM-6xx)
7 - % Range selector switch and zero fault switch
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Detcon Model DM Transmitter Test Fixture
3.0 Specifications
Compatible withthe Following Models
Model Series DM-524x, DM-550x, DM624x
Input Power
100-240VAC, 50 / 60Hz
Power Consumption
< 17 Watts
Digital Current Meter
Accuracy: ± 0.3% FS
Warranty
Two year
Outputs
Serial RS-485 Modbus™
4.0 Operation
Before using the test fixture, the technician should first be familiar with the operation of
Detcon DM series toxic gas sensors. Review the applicable sensor instruction manual(s)
for detailed operating instructions.
The test fixture is designed to verify performance of the Detcon DM series transmitters
only. The test fixture circuitry mimics the sensor portion of the complete sensor
assembly.
NOTE 1: The test fixture is designed to be used with only one transmitter at a time.
Plugging more than one transmitter in the test fixture at the same time (P1 and P2) will
cause erroneous readings.
NOTE 2: Reference Figure 1 for location of test fixture components. Before starting
verify that SW1 is in the “0” position.
NOTE 3: Model series DM-4xx loop powered transmitters are not compatible with this
test fixture.
4.1 DM-5xx Transmitters
Require tools:
Detcon PN 327-000000-000 MicroSafe™ Programming Magnet
NOTE: These instructions cover testing of the main features of the DM-5xx transmitter.
See the applicable DM-5xx instruction manual for a complete list of program features
and detailed operating procedures.
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Detcon Model DM Transmitter Test Fixture
1 - Turn the power switch on. The mA LED meter should illuminate.
2 - Plug the DM-5xx transmitter into P1.
3 - Perform a zero cal.
a) Enter the calibration menu by holding the programming magnet stationary over
“PGM 1” for 3 seconds until the display reads “1-ZERO 2-SPAN”, then
withdraw the magnet. Note that the “CAL” LED is on. Also note that the CAL
LED is illuminated and that the mA Output LED meter on the test fixture indicates
2.0 mA.
b) Next, enter the zero menu by holding the magnet stationary over “PGM 1” for 3
seconds until the display reads: “ZERO 0%”, then withdraw the magnet. The
sensor has now entered the auto zero mode. When it is complete the display will
read “ZERO COMPLETE” for 5 seconds and then return to the normal operations
menu, “0 % LEL”. Note that the mA Output LED meter on the test fixture
indicates 4.0 mA.
4 - Perform a span cal.
NOTE: DM series transmitters are universal and are programmed to operate at a specific
range as well as calibration level (see the DM-5xx instruction manual for further
information). To do a proper span cal, you must know the range and calibration level of
your transmitter. In most instances the calibration level is set to half of the range. In this
case, when performing a span cal, you will set SW1 to 50% of scale regardless of what
ppm range is requested by the transmitter during the calibration procedure.
a) Enter the calibration menu by holding the programming magnet stationary over
“PGM 1” for 3 seconds until the display reads “1-ZERO 2-EXIT”, then withdraw
the magnet.
b) From the calibration menu “1-ZERO 2-EXIT” proceed into the span adjust
function by holding the programming magnet stationary over “PGM 1” for 3
seconds until the display reads “APPLY ## PPM” then withdraw the programming
magnet. Note that the CAL LED is illuminated and that the mA Output LED meter
on the test fixture indicates 2.0 mA.
c) Turn SW1 to the “50%” position.The display will change to “AUTOSPAN ##
PPM”. When the sensor signal is stable it will auto span to the requested
concentration and the display will change to “SPAN COMPLETE” for two
seconds and then “REMOVE GAS”. Turn SW1 back to the “0” position. The
display will return to the normal operation menu, “0 PPM ###”.
5 - Check different ranges. Turn SW1 to each position (0, 10, 25, 50, 100) and verify a
matching transmitter display reading (±10%). These position settings are the % of the full
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Detcon Model DM Transmitter Test Fixture
scale range of the transmitter so calculate the proper reading accordingly. For example, If
the range of the transmitter is 0-100 ppm, the reading will equal the number indicated by
the SW1 position. If the range of the transmitter is 0-50 PPM, the reading will equal half
of the number indicated by the SW1 position, and so on. The 100 position will cause an
over-range condition resulting in the display flashing “### PPM ###”. Also verify an
LED mA output reading of 4.0 mA (0), 5.6mA (10), 8.0mA (25), 12.0mA (50), and
20.0mA (100). Return SW1 to the “0” position.
6 - Check zero fault. Turn SW1 to the zero fault position and note the “FLT” LED on the
transmitter illuminates and the display reads “Zero Fault”. Also note that the mA output
LED display indicates a reading of 000. Return SW2 to the NORMAL position.
4.2 DM-550 and DM-6xx Transmitters
Require tools:
Detcon PN 327-000000-000 MicroSafe™ Programming Magnet
NOTE: These instructions cover testing of the main features of the DM-550 and DM-6xx
transmitters. See the applicable DM-550 and DM-6xx instruction manual for a complete
list of program features and detailed operating procedures.
1 - Turn the power switch on. Both digital LED meters should illuminate.
2 - Plug the DM-550/DM-6xx transmitter into P2.
3 - Perform a zero cal.
a) Enter the calibration menu by holding the programming magnet stationary over
“PGM 1” for 3 seconds until the display reads “1-ZERO 2-SPAN”, then
withdraw the magnet. Note that the “CAL” LED is on. Also note that the CAL
LED is illuminated and that the mA Output LED meter on the test fixture indicates
2.0 mA.
b) Next, enter the zero menu by holding the magnet stationary over “PGM 1” for 3
seconds until the display reads: “ZERO 0%”, then withdraw the magnet. The
sensor has now entered the auto zero mode. When it is complete the display will
read “ZERO COMPLETE” for 5 seconds and then return to the normal operations
menu, “0 % LEL”. Note that the mA Output LED meter on the test fixture
indicates 4.0 mA.
4 - Perform a span cal.
NOTE: DM series transmitters are universal and are programmed to operate at a specific
range as well as calibration level (see the DM-550/DM-6xx instruction manual for further
information). To do a proper span cal, you must know the range and calibration level of
your transmitter. In most instances the calibration level is set to half of the range. In this
Page 6 of 8
Detcon Model DM Transmitter Test Fixture
case, when performing a span cal, you will set SW1 to 50% of scale regardless of what
ppm range is requested by the transmitter during the calibration procedure.
a) Enter the calibration menu by holding the programming magnet stationary over
“PGM 1” for 3 seconds until the display reads “1-ZERO 2-EXIT”, then withdraw
the magnet.
b) From the calibration menu “1-ZERO 2-EXIT” proceed into the span adjust
function by holding the programming magnet stationary over “PGM 1” for 3
seconds until the display reads “APPLY ## PPM” then withdraw the programming
magnet. Note that the CAL LED is illuminated and that the mA Output LED meter
on the test fixture indicates 2.0 mA.
c) Turn SW1 to the “50%” position.The display will change to “AUTOSPAN ##
PPM”. When the sensor signal is stable it will auto span to the requested
concentration and the display will change to “SPAN COMPLETE” for two
seconds and then “REMOVE GAS”. Turn SW1 back to the “0” position. The
display will return to the normal operation menu, “0 PPM ###”.
5 - Check different ranges. Turn SW1 to each position (0, 10, 25, 50, 100) and verify a
matching transmitter display reading (±10%). These position settings are the % of the full
scale range of the transmitter so calculate the proper reading accordingly. For example, If
the range of the transmitter is 0-100 ppm, the reading will equal the number indicated by
the SW1 position. If the range of the transmitter is 0-50 PPM, the reading will equal half
of the number indicated by the SW1 position, and so on. The 100 position will cause an
over-range condition resulting in the display flashing “### PPM ###”. Also verify an
LED mA output reading of 4.0 mA (0), 5.6mA (10), 8.0mA (25), 12.0mA (50), and
20.0mA (100). Return SW1 to the “0” position.
6 - Check zero fault. Turn SW1 to the zero fault position and note the “FLT” LED on the
transmitter illuminates and the display reads “Zero Fault”. Also note that the test fixture
fault LED illuminates and that the mA output LED display indicates a reading of 000.
Return SW2 to the NORMAL position.
7 - Check alarm relay outputs. Turn SW1 clockwise until both alarm LEDs on the
transmitter illuminate. Verify that both alarm LEDs on the test fixture also illuminate.
Return SW1 to the “0” position. If alarms on the transmitter are programmed for latching,
swipe the programming magnet over PGM1 or PGM2 to reset.
8 - RS-485 Out (P3). The DM-550x and DM-624x operate as Modbus slave devices. RS485 operation is checked by connecting to an RS-485 Modbus Master device. Reference
the applicable instruction manual for further information.
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Detcon Model DM Transmitter Test Fixture
5.0 Test Fixture Calibration
The DM Transmitter Test Fixture is calibrated at the Detcon factory. SW1 range
adjustment potentiometers are factory set and should not be adjusted by the user. If
calibration is required, return the test fixture to Detcon for calibration.
6.0 Warranty
Detcon, Inc., as manufacturer, warrants each DM Transmitter Test Fixture for a two year
period under the conditions described as follows: The warranty period begins on the date
of shipment to the original purchaser and ends two years thereafter. Should the test
fixture fail to perform in accordance with published specifications within the warranty
period, return it to Detcon, Inc., 3200 A-1 Research Forest Dr., The Woodlands, Texas
77381, for necessary repairs or replacement.
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