Vaisala HMM100 - Manual (Page 53)

Chapter 5 _______________________________________________________________ Maintenance
VAISALA ________________________________________________________________________ 51
CHAPTER 5
MAINTENANCE
This chapter provides information that is needed in basic maintenance of
the HMM100.
Changing the Filter
The filter on the probe should be replaced when it is damaged or dirty.
Do not attempt to clean the filter using compressed air, solvents, or
mechanical action. Wiping the filter may block its pores and/or deposit
residue on the filter.
1. Turn the filter counter-clockwise to loosen it.
2. Remove the filter from the probe. Be careful not to touch the
sensors with the filter. Without the filter in place, the sensors are
easily damaged – handle the probe carefully.
3. Check that the O-ring is undamaged and in place.
4. Install a new filter on the probe, and tighten it so it is finger-tight.
Make sure the filter sits straight and meets the threads properly.
New filters can be ordered from Vaisala. For available filters, see section
Filter Types on page 14. The order codes of the filters are listed in
section Options and Accessories on page 68.
Changing the Sensor
The user can replace the HUMICAP180R sensor with a new one. The
new sensor must be of the HUMICAP180R type. Do not attempt to use a
different sensor type.
NOTE Replacing the sensor is repair maintenance, and it is not necessary in
normal operation. If the accuracy of the module does not seem to be
within specification, it is more likely that the module is in need of
calibration and adjustment, and not sensor replacement. Refer to section
Calibration on page 53.