Detcon TP-700 SIL 2 Safety Manual - Manual (Page 5)

This proof test, commonly referred to as a “gas bump test”, requires application of high accuracy compressed calibration
gas to the detector while in NORMAL operational mode and inspecting the 4-20 mA signal output level to ensure that the
signal output is accurately indicative of the applied test gas concentration.
Warning:
Any external alarm equipment, systems or signaling devices that could be automatically initiated by
performing this test must be disabled or bypassed before performing this test!
When test gas is flowing into the detector, inspection of proper analog signal level output can be made by reading the
analog signal output displayed on the control device. The criteria used for inspection pass is a stabilized response signal
within +/- 10% of applied gas level or +/- 2 ppm (the greater of). Use a test gas value that is 50% of selected range. If
response test is not within acceptable limits, then a Full Calibration procedure must be performed and the Gas Response
Proof Test re-performed.
13.1 FULL CALIBRATION
Tools Required:
Span Calibration Gas Cylinder - H2S/background Air (50% of selected range)
Calibration Kit provided by Detcon
Programming magnet
Full Calibration shall be conducted when required The procedure for performing the Full Calibration is in
the Calibration section of the TP-700 instruction manual. In all cases the model TP-700 gas detector
should be allowed to warm up for 24 hours minimum before conducting a Full Calibration.
Warning:
The 4-20mA output from the TP-700 will drop to 2mA during the Full Calibration
Successful completion of the Gas Response Proof Test must be recorded and documented in the SIS
logbook. If the Full Calibration is performed, it should also be documented in the SIS logbook.
14 OUTPUT RESPONSE PROOF TEST
Tools Required: Span Calibration Gas Cylinder (50 ppm H2S/balance Air or mid-scale of range used)
Calibration Kit provided by Detcon
The Output Proof Test is performed as follows:
1. Inhibit alarm response at the control device.
2. Apply test gas (50% of FS Range of H2S ppm/balance Air) to the detector. Verify correct 4-20mA output signal
at the control device.
3. Re-activate alarm response at the control device.
15 FAULT/FAILURE ACTION PLAN
In the event that a Full Calibration does not result in acceptable Gas Response Proof test, then the standard Maintenance,
Troubleshooting, and Device Repair and Return Procedures are listed in the TP-700 instruction manual must be followed.
Any failure to successfully complete the Gas Response Proof Test must be recorded and documented in the SIS logbook.