User guide

Chapter 10 _____________________________ Calibrating and Adjusting the Probes
VAISALA __________________________________________________________53
Adjustment with Two Probes
You need to have two probe handles and two probes: one calibrated
probe and the probe to be adjusted. It is recommended to carry out the
adjustment in a stable environment and near the concentration values in
which the device is used.
Connect the probes to connectors I and II in the bottom of the indicator.
1. Turn on the GM70.
2. Take the probe you want to adjust. Unscrew the probe handle screw
to expose the adjustment button (see Figure 16 on page 48). Press
the button with a small s
crewdriver. When pressing the button,
indicator turns to adjusting mode.
3. Select
CO2, press SELECT.
4. Press YES to give the ambient pressure and temperature values.
Remember to check that pressure and temperature values are the
same with both probes. To continue adjusting press EXIT.
5. Now the adjustment mode is on. Press GRAPH to see when the
readings have stabilized. Go back and press ADJUST to select the
adjustment method.
6. Select To same as CO2, press SELECT and YES.
7. Adjustment is complete. Press BACK-EXIT to return to the basic
display.
8. Replace the screw onto the adjusting button.