Gas Monitor
Total Analytical Solution 
D-2-4, Setia Walk, Pusat Bandar Puchong,
47160 Puchong, Selangor, Malaysia
Tel: + 6012-921 3877; 603-5879 7121
Fax: +018 635 1593
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Infra-red pellistor replacement flammable gas detector


IREX is a sinter-free, fully featured infrared gas detector that produces an mV Wheatstone Bridge output as used on conventional pellistor based systems.

IREX replaces old pellistor heads by simply mounting on the original junction box and connecting to the original cable. The IREX concept enables upgrade to dual-wavelength IR gas detector technology without incurring the very significant costs associated with replacing the control system and re-installation.

The problem with pellistors

Pellistors (or Catalytic Beads) have been the flammable gas sensor of choice for oil and gas applications and general industry. Pellistors do however have several technical limitations:

  • They do not fail safe: pellistors are easily poisoned by substances such as silicones, sulphur and lead, rendering them insensitive to gas.
  • Pellistors must be operated behind a sinter (flame arrestor) which may become blocked, thus preventing gas from reaching the sensor.
  • Pellistors are high maintenance: sensors must be regularly tested with gas to ensure they are operational.
  • Pellistors typically last 3-5 years only.
  • Pellistors may burn-out if exposed to flammable gas concentrations above 100% LEL.
  • Pellistors need oxygen to be present to work otherwise their efficiency reduces

IREX overcomes all of these issues and delivers highly dependable and rapid gas detection with no un-revealed failures.




Low power

  • IREX consumes less than 1W of power - ensures compatibility with a wide range of control systems


  • Independantly tested for reliability and performance in harsh offshore conditions by Micropack Engineering Ltd - demonstrates IREX will operate dependable in any application
  • 3rd party approval to the performance standard EN60079-29-1
  • Employs sophisticated systems and algorithms - ensures reliable operation at all times
  • T90 response time of less than 4 seconds - rapid indication of hydrocarbon gas hazards
  • Optical components are treated with a STAY-CLIR coating - prevents partial obscuration in condensing atmospheres

Easy to maintain

  • No adjustments are necessary at the detectors, zero and span adjustments (if required) are performed at the control panel only - saves significent time and cost
  • Test can be applied remotely via a tube to the standard weather cover
  • Sinter-free operation - unlike a pellistor sensor, there is no risk of a sinter becoming blocked



D-2-4, Setia Walk, Pusat Bandar Puchong,
47160 Puchong, Selangor, Malaysia

Tel: + 6012-921 3877; 603-5879 7121
Fax: +018 635 1593