Calibration and adjustment, Opening and closing the adjustment mode, Chapter 7 – Vaisala HMT330 User Manual
Page 157: Chapter 7, calibration and adjustment, pr, Calibration and adjustment on pa
Chapter 7 ___________________________________________________ Calibration and Adjustment
VAISALA _______________________________________________________________________ 155
CHAPTER 7
CALIBRATION AND ADJUSTMENT
The HMT330 is fully calibrated and adjusted as shipped from factory.
Typical calibration interval is one year. Depending on the application it
may be good to make more frequent checks. Calibration must be done
always when there is a reason to believe that the device is not within the
accuracy specifications.
It is recommended that calibration and adjustment should be carried out
by Vaisala. For contact information of Vaisala Service Centers, see
Calibration and adjustment is carried out either by using the push-keys on
the motherboard, through the serial port or with the optional
display/keypad.
(Vaisala portable instruments HM70 and HMI41 can also be used).
Opening and Closing the Adjustment Mode
1.
Open the transmitter cover. The buttons needed in adjustment are
on the left-hand side of the motherboard.
2.
If the chemical purge option is available, it should be carried out
always before calibration. To start chemical purge press
simultaneously two PURGE push-keys (on the motherboard) for a
few seconds. Red indicator LED flashes with short pulses until
purge is complete (up to 6 minutes).
3.
Press the ADJ key to open the adjustment mode.
4.
Press the ADJ key again to close the adjustment mode.