Vaisala GM70 - Manual (Page 52)

USER'S GUIDE ______________________________________________________
52 _____________________________________________________ M010139EN-G
5. Take out the screw from the GM70 probe handle to expose the
adjustment button (see Figure 16 on page 48). Press the button with
a small screwdriver. When pressing the button, the indicator turns
to adjusting mode.
6. Press OK to confirm the adjusting.
7. Select CO2 , press SELECT.
8. Press YES to give the ambient pressure and temperature values.
To continue adjusting press EXIT .
9. 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.
10. Select 1-point adjustment , press SELECT . Press READY if the value
has stabilized.
11. Give the reference concentration value by using the arrow buttons.
Examples: For a zero-point adjustment using pure nitrogen (N
2
)
enter value 0 ppm.
For other reference gases, the analyzed CO
2
concentration is
typically printed on the bottle. Use that value.
Take care that you give the correct value in correct unit, you
cannot revert the earlier values after accepting the new values.
Press
OK .
12. Confirm the adjustment, press YES . By pressing NO you return
to adjustment mode display.
13. Adjustment is complete. Press BACK-EXIT to return to the basic
display.
14. Shut off the gas flow.
15. Replace the screw onto the adjusting button.