Vaisala MM70 - Manual (Page 55)

Chapter 5 ___________________________________________ CALIBRATION AND ADJUSTMENT
14. Confirm the adjustment, press the YES key (by pressing the NO
key you return to adjustment mode display and no changes are
made). If the difference between two references is less than 50
%, adjustment can not be done.
15. Adjustment is done. To return to the basic display, first press the
BACK key, then press the EXIT key.
16. Replace the screw onto calibration key.
You can attach a sticker on the calibration key screw to seal the
calibration.
1-point Adjustment
Usually it is recommended to make an adjustment in two reference
humidities. If adjustment is done by using one reference humidity (1-
point adjustment), select the reference humidity so that it represents
the measuring environment. Make the adjustment in one point as
instructed in the previous section "2-point Adjustment" (select 1-point
adjustment and follow the display instructions).
Temperature Adjustment
Temperature adjustment in one or two points can be done if there is
reason to believe that the adjustment is changed. If adjustment is done
only in one point, reference condition shall represent the measuring
environment.
1. Take out the screw covering the calibration button (in the probe
handle).
2. Press the calibration key. For pressing, use tool with thin and
sharp point, such as small screwdriver. When pressing the key,
indicator turns to adjusting mode.
3. Select T, press the SELECT key.
4. Now the adjustment mode is on, press the ADJUST key to
select the adjustment method: 1-point adjustment or 2-point
adjustment.
VAISALA _______________________________________________________________________ 53