User`s guide

Chapter 6 _______________________________________________________________ Maintenance
VAISALA ________________________________________________________________________ 47
CHAPTER 6
MAINTENANCE
This chapter provides information that is needed in basic maintenance of
the DPT145.
Periodic Maintenance
Cleaning
The body of the transmitter can be cleaned by wiping with a moistened
lint-free cloth. Do not immerse the transmitter in liquid, and do not use
cleaning agents or solvents.
Calibration and Adjustment
DPT145 is fully calibrated as shipped from factory. If there is a reason to
believe that the device is not within the accuracy specifications, you can
perform a field check using the DM70 hand-held dewpoint meter, or an
MI70 indicator with another DPT145.
If the field check indicates that the DPT145 is not within its accuracy
specifications, contact a Vaisala Service Center or your local Vaisala
representative to have the DPT145 adjusted.
Field Check Using an MI70 Indicator
Vaisala recommends the following equipment for field checking:
- A fully charged MI70 indicator (the measurement display that is
included in the DM70 package)
- A calibrated reference probe that is suitable for the intended
measurement environment and dewpoint range. The DMP74C probe
is recommended for checking the dewpoint and temperature
measurement accuracy. For checking all parameters, you can use
another DPT145 transmitter as a reference.
- You also need a connection cable (Vaisala order code: 219980) to
connect the DPT145 to the MI70 indicator. If you have two DPT145
transmitters, you need two cables.