M-Sens WR
Online Moisture Measurement For Solids

The microwave sensor for continuous humidity measurement
in dry bulk solids

Simple retrofitting for measurement in container outlets, conveyor screws, on conveyor belts, slides etc.

  • Humidity ranges 0 … 65 % (depending on material)
  • Measurement accuracy 0.1 %
  • Online humidity measurement
  • Independent of the material flow
  • Temperature-resistant up to 120 °C
  • ATEX-certified
  • Recording of surface humidity and capillary humidity

What do you want to do?


The M-Sens WR is used for the continuous measurement of humidity on solids 
of all kinds.

The M-Sens WR sensor can ideally be used, for example in container outlets, conveyor belts, conveyor screws, mixers and conveyor dryers.

It is important that the measuring surface of the sensor is always covered with material. The M-Sens WR is a contact-measuring procedure. The ceramic disc (measuring surface) must always be covered with material.




The M-Sens WR-sensor works with precise high-frequency measurements and direct digitalisation of the measurement values and thus a high resolution.

Since the surface and capillary humidity of a material has a strong influence on its dielectric constant, the humidity can be determined exactly given a constant medium bulk density. By way of support, any fluctuations of the measuring value caused by the bulk density are balanced through an internal filter function. Temperature-related fluctuations of the measuring value are automatically compensated by the sensor. The calibration of the system can easily be carried out by the operator. On the installed system, the calibration is a matter of pushing a button and entering the humidity reference value.

Mounting and Installation

A complete measuring system comprises the following

  • Welded flange with securing ring
  • Sensor with plug connector
  • MME 300 transmitter in a wall-mounted housing

The measuring probe is connected to the transmitter using a
shielded 4-core cable whose maximum length may be up to
1,000 ft.

The transmitter may take the form of a wall-mounted
housing including touch screen control and display or a
DIN-rail version. In the latter case a software package is
supplied for calibration.

Technical Data
Sensor Housing Stainless steel 1.4571
Protection category IP 65, DustEx 20 or GasEx (option)
Operating temperature Front end of sensor: – 20 … + 80 °C [-4 … +176 °F]Optional: – 20 … + 200 °C [-4 … +392 °F]Sensor electronic: 0 … 60 °C [+32 … +140 °F]
Max. working pressure 1 bar, optional 10 bar
Working frequency K-Band 24,125 GHz (± 100 MHz)
Transmitting power Max. 5 mW
Weight 1.3 kg
Dimension Ø 60, Ø 20, L 271 mm
Accuracy ± 2… 5 % in calibrated range
Transmitter Power supply 110/230 V, 50 Hz (optional 24 V DC)
Power consumption 20 W / 24 VA
Current consumption Max. 1 A at 24 V
Protection category IP 65 according to EN 60 529/10.91
Operating temperature -10 … + 45 °C [+14 … +113 °F]
Enclosure dimensions 258 x 237 x 174 (W x H x D)
Weight Approx. 2.5 kg
Interface RS 485 / RS 232 C (ModBus)
Cable glands 3 x M16 (4.5 – 10 mm Ø)
Screw terminals 0.2 – 2.5 mm² [AWG 24 – 14]
Current output signal 4… 20 mA (0… 20 mA), load < 500 Ω
Measurement value alarm relay output Relay with switching contact, max. 250 V AC, 1 A
Data storage Flash
Pulse output Open Collector – Max. 30 V, 20 mA
C-Box Size 98 x 64 x 35 mm (W x H x D)

Application Examples

Click on a desired application example to navigate to a detailed description.