Campbell Scientific HMP60 Temperature and Relative Humidity Probe - Manual (Page 23)

HMP60 Temperature and Relative Humidity Probe
8. Maintenance
The HMP60 Probe requires minimal maintenance. Check monthly to make
sure the radiation shield is free from debris. The white screen at the tip of the
probe should also be checked for contaminants.
When installed in close proximity to the ocean or other bodies of salt water
(e.g., Great Salt Lake), 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 saturated NaCl solution is 75%. A buildup of salt
on the filter or chip will delay or destroy the response to atmospheric humidity.
The filter can be rinsed gently in distilled water. If necessary, the chip can be
removed and rinsed as well (see Figure 8-1 and Section 8.1, Procedure for
Removing RH Chip). Do not scratch the silver chip while cleaning. It might
be necessary to repeat rinsing.
Shipping Cap
(remove prior
to installation)
Protective Cap
and Filter
9598 RH Chip
FIGURE 8-1. Exploded view of HMP60 (as shipped)
The offset and gain on the HMP60 electronics can not be adjusted as part of a
recalibration. Replace the RH chip as needed.
8.1 Procedure for Removing RH Chip
1. Unscrew the protective cap.
2. Hold the plastic sides of the RH chip and unplug it.
To prevent scratching, avoid touching the silver RH chip,
and handle the RH chip with care. CAUTION
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