ROTRONIC HM4 - Manual (Page 4)

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 4 of 41
Document Title
© 2014; ROTRONIC AG E-M-HM4-V0_08
1 Overview
The HygroMet4 (HM4) series of devices are digital humidity and temperature probes based on ROTRONIC
AirChip3000 technology. The probe permits heating of the sensor during humidity and temperature
measurement. It was developed for use in meteorological applications and wherever high humidity and the risk
of condensation on the sensor is likely.
The HM4 has two freely configurable and user adjustable linear analog outputs (voltage/current). It also has a
RS-485 interface for direct exporting of measured values with the HW4 software and configuration of the probe.
The manual E-M-HW4v3-F2-023 describes all software functions. Using the RS-485 interface, it is possible to
build a network of up to 64 simultaneously evaluable HM4 probes.
The HM4 offers the following user functions:
Simultaneous measurement and heating
Measurement of relative humidity and temperature and calculation of all psychrometric parameters
Freely programmable sensor heating (RoHumiHeat) prevents condensation on the sensor
Adjustable sensor cleaning (RoHumiClean) to minimise soiling of the sensor
SMD Thermo sensor element
Outstanding accuracy and repeatability
Integrated real-time clock
Freely scalable analog output signals
RS-485 interface
Calibration / Adjustment of humidity and temperature measured values
Simulation mode
User-specific device settings
Simple updating of the AirChip3000 firmware keeps the devices in the HM4 series up to date with improved
functionality.
DRAFT