Vaisala HMT310 - Manual (Page 65)

Chapter 5 _______________________________________________________________ Maintenance
VAISALA ________________________________________________________________________ 65
CHAPTER 5
MAINTENANCE
This chapter provides information that is needed in basic maintenance of
the HMT310.
Periodic Maintenance
Calibration Interval
HMT310 is fully calibrated and adjusted as shipped from factory. Typical
calibration interval is one year. In certain applications it may be
advisable to do more frequent checks. Calibration needs to be done
always when there is reason to believe that the device is not within the
accuracy specifications.
You can carry out calibration and adjustment by yourself, or you can
send the transmitter to Vaisala Service Centers for recalibration. For
more information on calibration, see section Calibration and Adjustment
on page 69.
Replacing Consumables
Changing the Filter
Replace the filter if it is contaminated. New filters are available from
Vaisala; see section Spare Parts and Accessories on page 93.
CAUTION Be careful when changing the filter, since it is easy to break the sensor
when the filter is removed.
CAUTION If the transmitter is installed in a pressurized chamber, always make sure
that the pressure of the chamber is equalized with the ambient pressure
prior to removing the transmitter. When the transmitter is removed for
maintenance, cap the hole with a capped nut. This way, the chamber can
be pressurized although the transmitter is not in place.
Plugs are available from Vaisala for ISO threaded connections.