General, Power supply, Measured parameters – ROTRONIC HM4 User Manual
Page 7: Draft

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 7 of 41
Document Title
© 2014; ROTRONIC AG
E-M-HM4-V0_08
3
General
3.1 Power Supply
The HM4 requires a power supply of 15...24 VDC (55 mA) for full functionality, but may already be operated on
5 VDC with the following restrictions:
Analog output only 0...1 V
RoHumiClean
function only available to a limited extent (see chapter 4.1.6)
Detailed Power Supply Specifications:
Operating State
Current Consumption
5 VDC, without heater
<35 mA
5 VDC, with heater
<55 mA
24 VDC, without heater
<20 mA
24 VDC, with heater
<30 mA
3.2 Measured Parameters
The HM4 measures relative humidity and temperature. The heated SMD humidity sensor allows simultaneous
heating and measurement. The temperature is measured at the tip of the probe by an external Pt100 sensor.
DRAFT