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MF420 200x200
  • Cl2
  • CO
  • H2S
  • NH3
  • NO2
  • O2
  • SO2


The measuring sensors of the product family MF420-C determine the concentration of toxic gases and vapors as well as oxygen in the air mixture, by using a specific electrochemical sensor. For further processing, the concentration is output by an 4 - 20 mA interface.

The sensor is characterized by its high measurement accuracy at low cross-sensitivity, even at low concentrations.

In combination with our limit monitors (GWZ) systems can be build up for the detection of toxic gases and vapors in the ambient air, e.g. storage facilities.

Measuring Ranges

The measuring ranges depend on the measured gas or vapor. For a table of ranges please refer to the product assortment. Other gases, vapors, and concentrations are also possible on request.


The device complies with the generic standards EN 61000-6-2 and EN 61000-6-3 and thus the EMC Directive 2004/108 / EC.

Maintenance and Service

The device is delivered already calibrated. The maintenance cycle must / should correspond to the given safety requirements. We recommend at least a semi-annual inspection of the equipment by qualified personnel. You can also use our service.

For more details, please refer to the technical data or ask our contact person.

Product NameProduct FeaturesProduct Code
MF420-C-CL2 Chlorine
Measuring range 0 - 10 ppm
MF420-C-CO-300 Carbon monoxide
Measuring range 0 - 300 ppm
MF420-C-CO-500 Carbon monoxide
Measuring range 0 - 500 ppm
MF420-C-CO-1000 Carbon monoxide
Measuring range 0 - 1000 ppm
MF420-C-H2S Hydrogen sulfide
Measuring range 0 - 50 ppm
MF420-C-H2S Hydrogen sulfide
Measuring range 0 - 200 ppm
MF420-C-NH3 Ammonia
Measuring range 0 - 100 ppm
MF420-C-NO2 Nitrogen Dioxid
Measuring range 0 - 50 ppm
MF420-C-NO2 Nitrogen Dioxid
Measuring range 0 - 100 ppm
MF420-C-O2 Oxygen
Measuring range 0 - 25 vol%
MF420-C-SO2 Sulfur Dioxide
Measuring range 0 - 100 ppm

Other gases & vapors on request. 

Principle of Measurement electro chemical sensor  
Power Supply terminal voltage minimum 14 V DC
Current approx. 30 mA
Connectors 2 screw terminals with reverse polarity protection 24 V DC ±5% and 4..20 mA
Ambient Temperature Sensor specific usually -20°C to +50°C
Air pressure 900 hPa to 1100 hPa  
Permissible Humidity 15 to 95% relative humidity non condensing
Output 4 - 20 mA  
Housing Alloy, red  
Protection class IP 54
Weight approx. 500 g
Dimensions (L x W x H) 90 x 85 x 65 mm
Connecting cable 2 x 1,5² CU + Functional ground shielded cable

Pin Assignment:

Pin Assignment

Product NameProduct FeaturesProduct Code
Replacement Sensor Set Consists of:
- Replacement sensor
- Sensor holder
- Sinter
- Seal
on request
Calibration Set Consists of:
- Test gas cap
- O-ring
on request