Detcon Model FP Transmitter Test Fixture
Operators Instruction Manual
June 17, 2008 * Document 3389 * Revision 1.1
3200 Research Forest Dr., Building A-1
Ph. 713-559-9200 / Fax 281-298-2868
DETCON, Inc.
The Woodlands, Texas 77387
www.detcon.com
Detcon Model FP 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 FP Transmitter Test Fixture
1.0 Description
The Detcon Model FP Transmitter Test Fixture is designed to test the operation of
Detcon Model FP Series LEL Transmitters. Models covered are series FP-424x, FP-524x,
FP-550x, and FP-624x.
2.0 Features
Reference figure 1 below for feature locations.
1 - Internal power supply and power switch
2 - Plug-in connector for FP-424 and FP-524 transmitters
3 - Catalytic bead open reference switch (SW2)
4 - Catalytic bead open active switch (SW3)
5 - Bridge voltage digital LED meter
6 - Plug-in connector for FP-550 and FP-624 transmitters
7 - mA output digital LED meter
8 - RS-485 output (FP-550 and FP-624)
9 - Fault and alarm relay output LEDs (FP-550 and FP-624)
10 - % LEL range selector switch
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Detcon Model FP Transmitter Test Fixture
3.0 Specifications
Compatible with the Following Models
Model Series FP-424x, FP-524x, FP-550x, FP624x
Input Power
100-240VAC, 50 / 60Hz
Power Consumption
< 17 Watts
Digital Current Meter
Accuracy: ± 0.3% FS
Digital Voltage Meter
Accuracy: ± 0.1% 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 FP series combustible gas sensors. Review the applicable sensor instruction
manual(s) for detailed operating instructions.
The test fixture is designed to verify performance of the Detcon FP 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 and that SW2 and SW3 are in the “NORMAL”
positions.
4.1 FP-424x Transmitters
Require tools:
Digital Volt-Ohm Meter (DVM)
Jewelers screwdriver
1 - Turn the power switch on. Both digital LED meters should illuminate.
2 - Plug the FP-424x transmitter into P1.
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Detcon Model FP Transmitter Test Fixture
3 - Check the bridge voltage. Insert DVM probes into the bridge “+” and “–“ test points.
Adjust the VOLT potentiometer on the transmitter until you achieve a reading of 2.70V.
Verify that the bridge voltage LED meter on the test fixture tracks closely with a reading
of 2.7V (±0.1V). Verify adjustability to either side of 2.70V.
4 - Perform zero cal. Verify SW1 is in the “0” position. Insert DVM probes into the
signal “+” and “–“ test points. Adjust the ZERO potentiometer on the transmitter until
you achieve a reading of 40mV. Verify that the mA output LED meter tracks closely with
a reading of 4.0mA. Verify adjustability to either side of 40mV.
5 - Perform span cal. Turn SW1 to the “50” position. With the DVM probes in the signal
“+” and “–“ test points, adjust the SPAN potentiometer on the transmitter until you
achieve a reading of 120mV. Verify that the mA output LED meter tracks closely with a
reading of 12.0mA. Verify adjustability to either side of 120mV. Do the same with the
FINE potentiometer to check adjustability.
6 - Check different ranges. Turn SW1 to the 10 position and verify a signal of
56mV/5.6mA (±5%). Turn SW1 to the 20 position and verify a signal of 72mV/7.2mA
(±5%). Turn SW1 to the 100 position and verify a signal of 200mV/20.0mA (±5%).
7 - Check signal fault (open active). Toggle SW3 to the OPEN position and note the
“DET FLT” LED on the transmitter illuminates. Return SW3 to the NORMAL position.
NOTE: The test fixture does not check for bridge fault on the FP-424C transmitter.
4.2 FP-524x Transmitters
Require tools:
Detcon PN 327-000000-000 MicroSafe™ Programming Magnet
NOTE: These instructions cover testing of the main features of the FP-524x transmitter.
See the applicable FP-524x 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 FP-524x transmitter into P1.
3 - Set the bridge voltage.
a) At the transmitter, enter the programming menu by holding the programming
magnet stationary over “PGM 2” for 30 seconds until the display reads “VIEW
PROG STATUS”, then withdraw the magnet.
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Detcon Model FP Transmitter Test Fixture
b) Next, scroll to the “SET BRIDGE VOLTS” listing and then hold the
programming magnet over “PGM 1” for 3 seconds. The menu item appears as
“BRIDGE @ #.## VDC”.
c) Use the programming magnet to make an adjustment to “PGM 1” to increase or
“PGM 2” to decrease the bridge voltage. Set the voltage to 2.7 VDC. Note that the
LED meter on the test fixture tracks the reading (±0.1V).
d) Exit to the programming menu by holding the programming magnet over
“PGM1” for 3 seconds, or automatically return to the programming menu in 30
seconds.
e) Exit back to normal operation by holding the programming magnet over “PGM
2” for 3 seconds, or automatically return to normal operation in 30 seconds.
4 - 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.
5 - Perform a span 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. Also note that the CAL LED is illuminated and that the mA
Output LED meter on the test fixture indicates 2.0 mA.
b) From the calibration menu “1-ZERO 2-SPAN” proceed into the span adjust
function by holding the programming magnet stationary over “PGM 2” for 3
seconds until the display reads “APPLY 50% LEL” then withdraw the
programming magnet.
c) Turn SW1 to the “50” position. The display will change to “AUTOSPAN 50%”.
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 % LEL”.
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Detcon Model FP Transmitter Test Fixture
6 - Check different ranges. Turn SW1 to each position (10, 20, 50, 100) and verify a
matching transmitter display reading (±2%). The 100 position (see note below) will cause
an over-range condition resulting in the display flashing “100% LEL”. Also verify an
LED mA output reading of 5.6mA (10), 7.2mA (20), 12.0mA (50), and 20.0mA (100).
Return SW1 to the “0” position.
NOTE: Optimally, when SW1 is in the 100% LEL position, the FP-524 display will
indicate a flashing 100 and the mA Output display on the tester will read 20.0. However,
a signal clipping zener diode on the transmitter may begin to activate in the high end of
the range prematurely on some transmitters causing a lower reading. The size of the error
may vary between transmitters. A reading as low as 80% is possible. From a safety
standpoint, the premature clipping occurs far above industry alarm set points.
7 - Check signal fault (open reference). Toggle SW2 to the OPEN position and note the
“FLT” LED on the transmitter illuminates and the display reads “Sensor Fault”. The mA
output LED will also indicate “00.0”. Return SW2 to the NORMAL position.
8 - Check signal fault (open active). Toggle SW3 to the OPEN position and note the
“FLT” LED on the transmitter illuminates and the display reads “Sensor Fault”. The mA
output LED will also indicate “00.0” Return SW3 to the NORMAL position.
4.3 FP-550x and FP-624x Transmitters
Require tools:
Detcon PN 327-000000-000 MicroSafe™ Programming Magnet
NOTE: These instructions cover testing of the main features of the FP-550x and FP-624x
transmitters. See the applicable FP-550x and FP-624x 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 FP-550x/FP-624x transmitter into P2.
3 - Set the bridge voltage.
a) At the transmitter, enter the programming menu by holding the programming
magnet stationary over “PGM 2” for 30 seconds until the display reads “VIEW
PROG STATUS”, then withdraw the magnet.
b) Next, scroll to the “SET BRIDGE VOLTS” listing and then hold the
programming magnet over “PGM 1” for 3 seconds. The menu item appears as
“BRIDGE @ #.## VDC”.
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Detcon Model FP Transmitter Test Fixture
c) Use the programming magnet to make an adjustment to “PGM 1” to increase or
“PGM 2” to decrease the bridge voltage. Set the voltage to 2.7 VDC. Note that the
LED meter on the test fixture tracks the reading (±0.1V).
d) Exit to the programming menu by holding the programming magnet over
“PGM1” for 3 seconds, or automatically return to the programming menu in 30
seconds.
e) Exit back to normal operation by holding the programming magnet over “PGM
2” for 3 seconds, or automatically return to normal operation in 30 seconds.
4 - 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.
5 - Perform a span 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. Also note that the CAL LED is illuminated and that the mA
Output LED meter on the test fixture indicates 2.0 mA.
b) From the calibration menu “1-ZERO 2-SPAN” proceed into the span adjust
function by holding the programming magnet stationary over “PGM 2” for 3
seconds until the display reads “APPLY 50% LEL” then withdraw the
programming magnet.
c) Turn SW1 to the “50” position. The display will change to “AUTOSPAN 50%”.
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 % LEL”.
6 - Check different ranges. Turn SW1 to each position (10, 20, 50, 100) and verify a
matching transmitter display reading (±2%). The 100 position (see note below) will cause
an over-range condition resulting in the display flashing “100% LEL”. Also verify an
LED mA output reading of 5.6mA (10), 7.2mA (20), 12.0mA (50), and 20.0mA (100).
Return SW1 to the “0” position.
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Detcon Model FP Transmitter Test Fixture
NOTE: Optimally, when SW1 is in the 100% LEL position, the FP-524 display will
indicate a flashing 100 and the mA Output display on the tester will read 20.0. However,
a signal clipping zener diode on the transmitter may begin to activate in the high end of
the range prematurely on some transmitters causing a lower reading. The size of the error
may vary between transmitters. A reading as low as 80% is possible. From a safety
standpoint, the premature clipping occurs far above industry alarm set points.
7 - Check signal fault (open reference). Toggle SW2 to the OPEN position and note the
“FLT” LED on the transmitter and the “FLT” LED on the test fixture illuminates and the
display reads “Sensor Fault”. The mA output LED will also indicate “00.0”. Return SW2
to the NORMAL position.
8 - Check signal fault (open active). Toggle SW3 to the OPEN position and note the FLT,
ALM1, and ALM2 LEDs on the transmitter illuminate and the display reads “Sensor
Fault”. Note also the FLT, ALM1 and AM2 LEDs on the test fixture illuminate. The mA
output LED will also indicate “00.0”. Return SW3 to the NORMAL position.
9 - 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.
10 - RS-485 Out (P3). The FP-550x and FP-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.
5.0 Test Fixture Calibration
The FP 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 FP 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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