ROTRONIC HM4 - Manual (Page 15)

E-M-HM4-V0_08
ROTRONIC AG
Bassersdorf, Switzerland
Document Code Unit
HM4 Humidity and Temperature Probe with
Heated Sensor
Instruction Manual
Document Type
Page 15 of 41
Document Title
© 2014; ROTRONIC AG E-M-HM4-V0_08
4.1.5 Sensor Heating (RoHumiHeat)
The sensor heating can be operated in three different modes.
Permanent
Time-dependent
Value-dependent
Start Response
When changing from an unheated to a heated state, there is a transient phase in which the sensor is heated to
above ambient temperature. Values measured by the probe are not refreshed for a time of 60 seconds until the
heater has stabilised at the set temperature.
Stop Response
When changing from a heated to an unheated state, there is, analogously to the start response, a transient
phase in which the sensor cools down to ambient temperature. The probe does not refresh measured values
for a time of four minutes after being switched off until this state has been reached.
Sensor Heating (RoHumiHeat), Permanent
ROTRONIC recommends this operating mode! It guarantees the highest operating reliability and measuring
accuracy!
The humidity sensor is heated permanently. The heating rate is controlled by the ambient temperature.
The nominal temperature can be set with the HW4 software at will between 0.1 and 10 °C above ambient temperature.
The mode "permanent sensor heating" is factory set on a difference of 3 °C above ambient temperature. Temperature
differences of more than 3 °C between the sensor and environs caused by heating can have effects on the external
temperature measurement. This is particularly possible in stagnant air because the heat energy is then not dissipated
efficiently.
The function "permanent sensor heating" can be enabled/disabled with the HW4 software.
DRAFT