Heath Consultants GT Series - Manual (Page 118)

11-14
USER HANDBOOK
The instrument can however still be used to detect and
alarm on the other sensor(s) fitted.
The faulty sensor will cause the instrument to display a
flashing spanner symbol to warn the user that this sensor
is not working correctly, as shown in Fig. 11.8:
alternating with
Fig. 11.8 Zero Fault
11.6.3 Sensor Fault
There are two types of sensor fault as illustrated in the
following displays:
1) If a “ZERO FAULT” flag and a flashing spanner
symbol appear, alternating with a zero reading as
shown in Fig. 11.9, apply relevant test gas (LEL in
example) for two minutes and allow the display to
return to zero, then switch instrument Off and On
again.