Maintenance; Changing The Humicap 180 Humidity Sensor; Chemical Tolerances Of The Humicap 180 Sensor; Using The Hmp46 In High Temperatures - Vaisala HUMICAP HMP41 User Manual

M210316EN-A
9.

MAINTENANCE

9.1

Changing the HUMICAP 180 humidity sensor

Unscrew the plastic grid (HMP41&45) or the sintered filter (HMP46).
Remove the damaged sensor and mount a new HUMICAP
sensor in its place. Handle the sensor with care. Calibrate the probe using a
two-point calibration procedure (see section 5.2.4).
9.2

Chemical tolerances of the HUMICAP 180 sensor

Long-term exposure of the HUMICAP sensor to certain chemicals and gases
may affect the characteristics of the sensor and shorten its life. The following
table gives the recommended maximum ambient concentrations of some
chemicals:
Organic solvents
Aggressive chemicals (e.g. strong acids
such as SO
Weak acids
Bases
If necessary, request detailed information on allowed concentrations from
Vaisala representatives.
9.3

Using the HMP46 in high temperatures

The HMP46 probe can be temporarily used in high temperatures. For example,
the probe can be installed in +180 °C for 30 minutes provided that the probe
handle and 10 cm of the metal tube are at room temperature. When the
HMP46 probe is used in high temperatures, it warms up. Take necessary
precautions before touching it!
, H SO , H S, HCl, Cl
2 2 4 2
ppm (typ.)
1000...10 000
1...10
, etc.)
2
100...1000
10 000...100 000
HMI41 AND PROBES
Operating Manual
®
180 humidity
37