GASMAX II Operation & Maintenance Manual, Revision 7.0
Page 30
CALIBRATION PROCEDURE
Before beginning calibration, make sure you have the following items: A cylinder of calibration gas, fixed
flow regulator and an appropriate calibration cup connected to the regulator via a length of flexible
tubing. A
cylinder of ‘zero air’
is always recommended and may be necessary if the absence of target gas
cannot be confirmed. GDS Corp recommends a flow rate of 0.5 liters / minute for standard gases and a
flow rate of 1.0 liters / minute for highly reactive gases such as chlorine or chlorine dioxide.
To calibrate a GASMAX II detector:
1.
For dual channel units, press the NEXT key until that the DATA Display for the desired channel is
shown.
2.
Enter CAL MODE by pressing the DOWN / CAL key and within 5 seconds press the EDIT key.
3.
The screen will display an APPLY ZERO message. Using the setup shown in Fig. 5-1, apply clean ZERO
air unless it can be guaranteed that no target gas is present. After the reading stabilizes, press the
EDIT key to complete the ZERO calibration.
4.
If the zero calibration is successful, a ZERO CAL SUCCESSFUL message is displayed, followed by an
APPLY SPAN message.
5.
Disconnect the zero air cylinder and connect the span gas cylinder and apply the SPAN gas After the
reading is stable, (approximately 1 minute, could be as long as 2-3 minutes) press the EDIT key to
complete the SPAN GAS calibration. If the SPAN calibration is successful, the display flashes SPAN CAL
SUCCESSFUL followed by REMOVE CAL GAS.
6.
Immediately shut off the regulator and remove the calibration cup. At the end of the CAL PURGE delay,
the GASMAX II output is re-enabled and the unit is fully operational.
NOTE
: A CAL MODE INFO SCREEN IS AVAILABLE TO VIEW CERTAIN CAL MODE PARAMETERS DURING
CALIBRATION. HOLD THE UP KEY FOR 5 SECONDS DURING CAL MODE TO DISPLAY THIS SCREEN.
Calibration Cup
Fixed Flow Regulator
Cylinder of
Calibration Gas
or Zero Air
Flexible Tubing