Manual

Chapter 6 ____________________________________________________ Calibration and adjustment

VAISALA ________________________________________________________________________ 55

CHAPTER 6

CALIBRATION AND ADJUSTMENT

This chapter describes the calibration and adjustment procedures. Note

that after adjustment, the original calibration certificate shipped with the

product is not valid anymore.

The MMT318 and MMT317 are calibrated as shipped from the factory.

Typical calibration interval is one year. Depending on the application it

may be good to make the first calibration check earlier.

NOTE

When measuring moisture in transformer oil, the recommended

calibration interval is 3 years.

Relative humidity calibration must be done always after sensor change.

Calibration of the MMT318 and MMT317 can be carried out by the user

according to the instructions given in this chapter.

Vaisala recommends using the calibration services offered by Vaisala.

Vaisala Service Centers perform calibrations and adjustments as well as

repair and spare part services, and offer accredited calibrations and

maintenance contracts.

For Vaisala Service Center contact information, see

www.vaisala.com/servicecenters.

Calibration services can also be ordered online at store.vaisala.com.

CAUTION

If you think the MMT310 is not measuring correctly, calibration and

adjustment is not the first thing to do. Try the following first:

Make sure heat sources or temperature differences are not interfering

with the measurement.

Always wait for the measurement to stabilize.

NOTE

For an introduction to calibration, order or download the free calibration

book from Vaisala at the

following address: