TS4000H
42
4.8 Gas Check Mode
Figure 17: Gas Check
The sensor’s response can be checked without activating external alarms by placing the
TS4000H in Gas Check Mode. In this mode, the alarm relays are inhibited and the analog
output is fixed at 1.5 mA.
NOTE:
Gas Check Mode is not accessible when either an O
2
sensor or no sensor is installed
in the TS4000H.
4.8.1 Gas Check Procedure
To Run Gas Check Mode for All Sensors Except O
2
1. Apply and hold the magnet over the GM logo on the Base Unit cover. Remove the
magnet when three dashes “
---
” appear in the display window. This action places the
unit into Gas Check Mode.
2. The
“
---
“ flashes while the settings are being set to zero.
3. Once the unit has been set to zero, “
gAS
” appears in the display window.
4. Apply the test gas to the sensor, the value of the gas concentration is then indicated by
the flashing display (with readings typically stabilizing within one to two minutes).
5. When the reading has stabilized and the test is complete, remove the gas. When the
gas concentration drops below 5% FS the unit returns to normal operation.
NOTE:
The test gas concentration must be at least 10% FS before the unit can complete the
Gas Check sequence. If the TS4000H is placed in the Gas Check Mode and no gas is
applied within ten minutes, the unit returns to normal operation. If the TS4000H is in
Gas Check Mode and gas is applied longer than ten minutes, the unit will also revert to
a Fault condition. Removing the applied gas will return the TS4000H to normal
operation.
4.8.1.1 Ending Gas Check Mode
Gas Check Mode can be ended after the zeroing stage and while the unit is waiting for gas to
be applied. Applying and removing the magnet over the GM logo, after the unit has been
zeroed and prior to gas being applied, will terminate the Gas Check Mode and save the zero
settings.
4.8.1.2 Aborting Gas Check Mode
Gas Check Mode can be aborted during the zeroing stage (prior to “
gAS
” being displayed) if
gas has not yet been applied to the sensor. Simply reapply and remove the magnet to the GM
logo on the Base Unit cover, and the unit returns to normal operation.
