Bump Test Conditions; Bump Test Procedure - GasTech D-Guard2 Operator's Manual

10.4. Bump Test Conditions

Bump tests must be carried out with the detector operating within its specified limits. Operating the
detector outside of its limits could cause performance problems or functional failure.

10.5. Bump Test Procedure

Bump testing involves applying test gas to the detector and observing the readings from it.
Readings should be obtained either from the detector's display or the controller display.
If it is required to monitor the current loop signal and there is no provision for accessing it within the installation
wiring, the detector enclosure must be opened to gain access to the test terminals on the main circuit board.
Current Loop Test Points
Do not short the test points to ground or connect to the shield or the signal return terminals. Doing so
may cause damage to the detector electronics.
Do not operate the unit with the cover removed if the installation area and or conditions do not
permit it. Current loop access must then be via connections in the safe area.
The bump test procedure should be carried out as follows (example assumes a 0 - 100ppm H
Decide on the appropriate method for viewing the readings.

Remove the splash-guard from the detector gas entry port - the splash-guard is removed via two 4mm

Allen key type screws. Attach the calibration plug (with attached 6mm hose) to the detectors gas
inlet port by gently pushing it into place.
Connect the hose to the purge gas cylinder regulator outlet.

Turn on the nitrogen supply and allow to run for about 60 seconds.

Observe the detector response (nitrogen still running).

The display reading should be 0.0 ± 0.1. The current loop output should be 4.00mA with a maximum

variation from ideal of ± 0.03mA.
Switch off the purge gas

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