Vaisala HMT360 - Manual (Page 71)

Chapter 6 __________________________________________________ Calibration and Adjustment
VAISALA_______________________________________________________________________ 69
High End Adjustment (HMT360 with Display)
1. After having made the low end adjustment, insert the probe 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.
2. The readings measured by the transmitter appear on the display, as
well as the text "Set Hi" on the lower left hand corner.
3. Wait at least 10 ... 15 minutes for the sensor to stabilize; use the
transmitter display to monitor the stabilization.
4. Press buttons Up and Dn to adjust the display and conclude the
adjustment with button E.
5. Restore the DIP switch settings. Set the calibration DIP switch to
position disabled (down).
One-Point Temperature Adjustment
1. Set the internal DIP switch Calibration Enabled/Disabled to
position ON and select T calibration by using switches 3 and 4 (see
section
DIP Switch Functions on page 45 ).
2. The temperature value measured by the transmitter appears on the
display as well as the text "Set Lo" on the lower left corner. If the
transmitter has no display, the LED indicator starts to blink.
3. Let the sensor stabilize; use a multimeter or the transmitter display to
monitor the stabilization.
4. Press buttons Up and Dn to adjust the display or multimeter reading
to correspond to the reference value (when using a multimeter
calculate the current value corresponding to the reference humidity by
using the equations presented in
Calculating Correspondence of
Current Values and Output Quantities on page 64 ).
5. Conclude the one-point adjustment by pressing button E twice.
NOTE Always use a high quality standard for adjusting the temperature.
NOTE If you use serial commands, please refer to section Adjustment
Commands on page 53 .