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6.
PROOF TEST
The proof test of the detector shall be undertaken to reveal dangerous faults,
which are not detected by the GS01 internal diagnostic tests. The below described
test sequence will excite the safety functions of the GS01 detector and thereby
verify these.
Before performing the test, always check that there is no unattended "Attenuated
optical beam" warning from the instrument (DIAG_STATUS bit no. 7 set, see
troubleshooting section in the user manual). If there is, the window and mirror in
the measuring cell shall be cleaned. Cleaning (if required) of the GS01 detector is
described in detail in the user manual [RD 1].
The proof test consists of the following steps:
1. Bypass the connected safety device(s) or take other appropriate actions to
avoid false tripping.
2. Use test gas with known concentration and:
a. at least 2.1%vol methane in synthetic air for Config-1,-129,-65, and -193.
b. at least 0.4%vol propane in synthetic air for Config-2,-130,-66, and -194.
3. Perform a validation of the GS01 detector as follows:
The weather cap is designed for validation, as it includes a 6 mm diameter
tube fitting for efficiently filling the GS01 measuring cell with a test gas
mixture. Apply the test gas through a 6 mm tube from a gas cylinder with
pressure regulator with a flow rate of at least 5 L/min. Note however that
the test gas will leak out during testing and leakage will depend on the wind
speed. Therefore, the measured gas concentration is normally lower than
stated on the test gas cylinder. It is not recommended to carry out
validation in stronger wind, or alternatively the weather cap has to be
covered on the outside in this case, i.e. by applying tape to the openings.
The function of the detector is positively validated as long as it responds to
the test gas with the required safety accuracy (cf. Table 8-1).
4. Monitor the detector output on the safety device to verify that the gas is
correctly detected. Note down the response time and verify that it is within
specification and not longer than 30 sec.
5. Remove the bypass from the connected safety device(s) and restore
normal operation. Remember to remove tape (if applied) from the weather
cap!
The proof test reveals 83% of the dangerous undetected faults identified during
the failure modes analysis.
The recommended proof test interval is minimum every second year.
PROOF TEST
GasSecure GS01
Safety Manual
13
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