7. Maintenance
7.1 Periodic maintenance
The humidity measurement accuracy of the HMP60 and HMP110 series probes should be
calibrated yearly. When calibration indicates that accuracy is not within specification:
• HMP60 and HMP63: change the INTERCAP
â
sensor.
• HMP110 and HMP113: adjust the measurement yourself, or have it adjusted at Vaisala.
Light cleaning of the probe and replacement of the filter should be done only when necessary.
7.1.1 Cleaning
The probe body can be wiped clean with a soft, lint-free cloth moistened with mild detergent.
Do not use solvents or compressed air.
Note that wiping the membrane filter or stainless steel sintered filter may block its pores
and/or deposit residue on the filter. If the filter is heavily contaminated, replace it.
7.1.2 Replacing filter
The filter on the probe should be replaced when it is damaged or dirty.
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. 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.
Order new filters from Vaisala.
More information
‣
‣
Spare parts and accessories (page 83)
‣
Maintenance and calibration services (page 95)
7.2 Calibration procedure
To calibrate your HMP60 or HMP110 series probe, you need a known stable humidity or
temperature reference, and a way to read the output of the probe (Vaisala Insight software,
analog output, serial output, the MI70 indicator, or the HM40 meter). As a humidity reference
you can use, for example, the Vaisala Humidity Calibrator HMK15.
The probe can be connected to a PC with Vaisala USB cable 219690, and to the MI70 indicator
with connection cable 219980. The HM40 meter does not need a specific connection cable.
Chapter 7 – Maintenance
55
