Concentration-measuring gas detectors DEX/P

DEX/P detectors are designed to measure gas or vapour concentration of explosive or toxic liquids or oxygen. They are equipped with analog current output in 4-20mA standard.

The detectors are designed to cooperate with measuring control units of the MDP group. They can also cooperate with any other control units working in standard 4-20mA input lines with current emission, after applying power limiter type MDPL1.

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.


  • 4-20mA standard analog output (passive);
  • easily interchangeable sensor unit and easy maintenance;
  • easy change of detected gas or calibration of the detector;
  • built-in temperature compensation;
  • catalytic or infra-red sensor for combustible gases or electrochemical sensor for toxic gases or oxygen;
  • sensor unit with “zero” and “span” regulation (calibration outside the detector);
  • low-cost operation;
  • easy fit to existing systems with 4-20mA standard inputs (using MDPL1 limiter);
  • 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

Offered models

Model Gas sensor module Sensor Substance/property Standard alarm thresholds or measuring range Supply voltage Net price C/G
Ex MS-P1K5/N Catalytic Liquefied petroleum gas (LPG)
0 ÷ 100
System powered 1,099.00 zł S
Ex MS-P1K/N Catalytic Methane (CH4)
0 ÷ 100
System powered 999.00 zł S
Ex MS-P3K/N Catalytic Volatile organic compounds (VOC)
0 ÷ 100
System powered 1,139.00 zł N
Ex MS-P4K/N Catalytic Ammonia (NH3)
0 ÷ 20
System powered 1,099.00 zł N
Ex MS-P7K/N Catalytic Hydrogen (H2)
0 ÷ 100
System powered 999.00 zł N
Ex MS-P2E/N Electrochemical Carbon monoxide (CO)
0 ÷ 500
System powered 1,149.00 zł N
Ex MS-P4E/N-X Electrochemical Ammonia (NH3)
500 ÷ 1000
System powered 1,149.00 zł N
Ex MS-P7E/N Electrochemical Hydrogen (H2)
0 ÷ 1000
System powered N
Ex MS-P9E/N Electrochemical Oxygen (O2)
0 ÷ 25
System powered 1,049.00 zł S
Ex MS-P1R2/N Infra-red Methane (CH4)
0 ÷ 100
System powered 1,849.00 zł S
Ex MS-P1R5/N Infra-red Liquefied petroleum gas (LPG)
0 ÷ 100
System powered 1,849.00 zł S
Ex MS-P3R/N-X Infra-red Volatile organic compounds (VOC)
0 ÷ 100
System powered 1,989.00 zł N
Ex MS-P8R/N Infra-red Carbon dioxide (CO2)
0 ÷ 5
System powered 1,849.00 zł N

Detection of substance/property in other areas or other substances/properties is possible = special execution, requires consultation.
In special cases, it is possible to select the detector parameters for a specific application = required analysis of the conditions of use.

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