Heath Consultants GT Series - Manual (Page 88)

8-4
USER HANDBOOK
8.5 DESCRIPTION OF PURGE BUTTON
OPERATION
8.5.1 Lights
To switch ON the backlight:
• Press and hold the Centre button
To switch ON the flashlight:
• Press and hold the Centre button again.
The backlight and flashlight are both timed to switch OFF
after two minutes. Both can be switched OFF by a third
press and hold the Centre button
8.5.2 Pump
To switch the pump ON and OFF:
• Press the RH button .
8.5.3 Manual Zero
To zero the reading (in fresh air):
• Press and hold ZERO .
Note: Pump must be switched ON to zero reading.