Sensor maintenance, 1 periodic maintenance, 1 cleaning – Campbell Scientific HMP155A Temperature and Relative Humidity Probe User Manual
Page 24: 2 changing the probe filter, Periodic maintenance, Cleaning, Changing the probe filter, 1. changing the filter
HMP155ATemperature and Relative Humidity Probe
8. Sensor Maintenance
The HMP155A Probe requires minimal maintenance. Check monthly to make
sure the radiation shield is free from debris. The filter at the end of the sensor
should also be checked for contaminates.
8.1 Periodic Maintenance
8.1.1 Cleaning
Clean the probe with a soft, lint-free cloth moistened with mild detergent.
8.1.2 Changing the Probe Filter
1. Remove the filter from the probe.
2. After removing the filter, check the O-ring and change it if necessary.
3. Install a new filter on the probe.
New filters can be ordered from Campbell Scientific or Vaisala.
FIGURE 8-1. Changing the filter
When installed in close proximity to the ocean or other bodies of salt water, a
coating of salt (mostly NaCl) may build up on the radiation shield, sensor, filter
and even the chip. NaCl has an affinity for water. The humidity over a
16