Vaisala HMP155 - Manual (Page 50)

USER'S GUIDE____________________________________________________________________
48 _______________________________________________________________ M210912EN-C
Sensor Heating
This function is optionally available only in probes with
HUMICAP
® 180RC or HUMICAP ® 180C composite sensors. It should be
used only with the heated probe.
The sensor heating is recommended for the high humidity environments
where even small temperature differences can cause water to condense
on the sensor. The sensor heating speeds up the recovery of the humidity
sensor from condensation.
Sensor heating starts-up when the relative humidity of the measuring
environment reaches the RH-value set by a user (RH-limit). You can
define the RH-sensor heating temperature as well as the duration of the
heating.
After the heating cycle, the humidity conditions are checked and new
sensor heating is performed if the predefined conditions are reached
again.
NOTE During the sensor heating, the outputs are locked to the values measured
before the heating cycle.
Setting Humidity Sensor Heating
When the HMP155 leaves the factory, the sensor heating follows the
factory default values. You can enable or disable the function, change the
RH-limit and define the heating temperature and duration of this
function.