Vaisala HMT360Series - Manual Low End RH Adjustment; Manual High End RH Adjustment (Two-Point)

Calibration and adjustment ____________________________________________________________
Vaisala _________________________________________________________________________ 50
Manual calibration
Low end adjustment
- Remove the filter and insert the probe head into a measurement
hole of the dry end reference chamber (e.g. LiCl: 11 %RH) in the
humidity calibrator.
NOTE
If you use serial commands, please refer to page 39.
− Set the calibration dip switch 2 to ENABLED (up) position and
select RH calibration by using switches 3 and 4 (see Chapter 5: Dip
switch functions).
- Press button C to ignore the automatic calibration procedure. The
humidity reading measured by the transmitter appears on the
display and on the lower left corner you can see the text SET LO. If
the transmitter has no display, the LED indicator is blinking.
- According to the calibrator used, wait at least 10 - 15 minutes for
the sensor to stabilize; use a multimeter or the transmitter display to
monitor the stabilization.
- Press the buttons ▲ and ▼ to adjust the display reading or
multimeter reading to correspond the reference value (when using a
multimeter calculate the current value corresponding to the
reference humidity by using the equations presented in page 46).
Press the button E to conclude the low end adjustment.
- If the low end adjustment is sufficient, press the button E again to
conclude the calibration and restore the dip switch settings; set the
calibration dip switch to position DISABLED (down). To continue
with the high end adjustment follow the instructions in next
chapter.
High end adjustment (two-point calibration)
- After having made the low end adjustment, insert the probe head
into a measurement hole of the NaCl (75 %RH) salt chamber in the
humidity calibrator. Please, note that the difference between the
two humidity references must be at least 30%RH.
NOTE
If you use serial commands, please refer to page 39.
- The readings measured by the transmitter appear on the display, as
well as the text, SET HI on the lower left hand corner. If the
transmitter has no display, the LED indicator lights up.