Maintenance, Cleaning, Calibration and adjustment – Vaisala GMW90 User Manual
Page 65: Adjustment methods, Chapter 5, Chapter 5, maintenance

Chapter 5 _______________________________________________________________ Maintenance
VAISALA ________________________________________________________________________ 63
CHAPTER 5
MAINTENANCE
This chapter provides information that is needed in basic maintenance of
the GMW90 series.
Cleaning
The body of the transmitter can be cleaned by wiping with a moistened
lint-free cloth. Do not use cleaning agents or solvents, or blow
pressurized air into the transmitter housing.
Do not attempt to clean contaminated measurement modules. Dirty
modules should always be replaced with new calibrated modules.
Calibration and Adjustment
GMW90 series transmitters are fully calibrated as shipped from factory.
GMW90 series transmitters have a display that makes it easy to compare
the measured readings against any portable calibration reference. Note
that depending on the ordered configuration, the display may be hidden
under the sliding cover.
Adjustment Methods
You can adjust the measurements in the following ways:
- 1-point adjustment using the trimmers under the sliding cover. See
section Adjustment Using Display and Trimmers on page 66.
- 1-point or 2-point adjustment using the service port. See the following
sections:
- Adjustment Using a Hand-Held Meter on page 67.
- Adjustment Using a Computer on page 68.
If adjustment is not enough to restore the measurement accuracy of the
transmitter, you can also replace the measurement modules. See section