Point adjustment – Vaisala HM70 User Manual
Page 64
User's Guide ______________________________________________________________________
62 __________________________________________________________________ M210297EN-E
stored into the memory of the HM70. Make the adjustment as
instructed in the following section 2-Point Adjustment (select
LiCl--NaCl
autom.
on item 9
and follow the display instructions).
2-Point Adjustment
Low humidity references 0 % (Nitrogen)/ 11.3 % (LiCl) and higher
humidity references 75 % (NaCl)/ 97 % (K
2
SO
4
) are recommended for
two-point adjustment. Ensure that the difference between the humidity
references is more than 50 %.
1.
When adjusting both relative humidity and temperature, please
make the temperature adjustment first.
2.
Check that the HM70 is switched on.
3.
If chemical purge option is available perform it before
adjustment, see page 34.
4.
Take out the screw from the probe handle to expose the
calibration button. Press the button with a small screwdriver.
When pressing the button, indicator turns to adjusting mode.
5.
Press
OK
to start the adjustment mode.
6.
Select
RH
, press
SELECT
.
7.
Press
YES
to check the environmental settings, to continue
directly adjustment press
NO
.
8.
Now the adjustment mode is on, press
ADJUST
to select the
adjustment method.
9.
Select
2-point adjustment,
press
SELECT.
Press
OK
to continue.
10.
Set the probe to a lower reference relative humidity. If using
HMK15 calibrator, use the adapter fitting (13.5 mm hole) with
probes HMP76 and HMP77.
You can follow the stabilization from the
GRAPH
display.
Press
READY
when the reading is stabilized.