DEX-31/N Ex

Device group: Threshold gas detectors
Device type: DEX/F
Device model: DEX-31/N

DEX/F detectors are designed to detect the presence of dangerous concentrations of gases or vapours of explosive or toxic liquids or oxygen. They signal exceeding two alarm thresholds (A1, A2) set in an interchangeable sensor module (thresholds set at the production stage). They are designed to work only with control modules type MD.

The detectors meet the essential requirements of Directive 2014/34/EU (ATEX) of the European Parliament and of the Council of 26 February 2014, on the harmonization of the laws of the Member States relating to protective systems intended for use in potentially explosive atmospheres, implemented by the Regulation of the Minister of Development on requirements for equipment and protective systems intended for use in potentially explosive atmospheres of 6 June 2016. (Journal of Laws 2016 item 817).

The detectors are devices with explosion-proof construction of flameproof cover type and can be used in zones 1 or 2 threatened with explosion of flammable gases or vapors classified as explosiveness group IIA, IIB or IIC, temperature classes T1, T2, T3, T4, T5 or T6.


  • detachable and interchangeable sensor unit guarantees easy maintenance and low cost operation;
  • easy change of detection gas or calibration of detector;
  • built in temperature compensation;
  • semiconductor or catalytic or infra-red sensor for combustible gases or electrochemical sensor for toxic gases or oxygen;
  • high temperature (up to +80°C) version available;
  • all detectors are calibrated in our own GAZEX Calibration Laboratory operating in accordance with PN-EN ISO/IEC 17025 (PCA accreditation No AP150).

Typical system configuration

Technical parameters

Gas sensor module Sensor Substance/property Standard alarm thresholds or measuring range
MS-31/N-X Semiconductor Volatile organic compounds (VOC)

Two-state outputs (threshold)
Possibility of working in potentially explosive atmospheres
ATEX certificate
Supply voltage
System powered
105 x 103 x 54 mm
Net price
889.00 zł N


Series Technical data Device information sheet Instruction manual Declaration of conformity

Suggested products

Splash-proof enclosures to protect detectors from adverse weather conditions and mechanical damage
Profiled tube guards to protect the detector from direct mechanical damage
Test kits for checking the correct functioning of detectors