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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

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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

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