Air Safety

ST-48 Hydrogen Sulfide Combustible Gas Monitor 0-30 ppm

The ST-48 Combustible Gas Monitor is ideal for facilities that require continuous monitoring of hydrogen sulfide. The enclosure is specifically designed to prevent an explosion. The monitor is well suited for environments such as refineries, natural gas locations, wastewater treatment plants, chemical plants, and any locations requiring LEL gas monitoring for combustible gases. The monitor is housed in a NEMA 4 explosion-proof enclosure suitable for Class 1, Group B, C, and D, Class 2, Group E, F, and G. PureAire’s durable, long-life LEL catalytic sensor will last 5-6  years in a normal environment without needing to be replaced.

  • LEL Combustible Gas Analyzer with 0-100% or 0-4% of LEL
  • Designed for Combustible Gases including Hydrogen Sulfide
  • Gas Sampling for Vessels or General Safety with Wall Mount
  • Explosion-Proof Enclosure
  • Non-Intrusive Calibration
  • Local Digital Display
  • 4-20 mA Analog Output
  • 2 Configurable High/Low Relays
  • Long Life LEL Catalytic Sensor Average, 5-6 years

The ST-48 LEL gas detector is housed in a NEMA 4 Explosion Proof Enclosure and is available for hydrogen sulfide (H2S). Capable of monitoring the percentage of LEL combustible gas, the ST-48 is a perfect monitoring solution for providing worker protection in natural gas locations, paper mills, wastewater treatment facilities, the oil and gas industry,  and other areas requiring hazardous monitoring for hydrogen sulfide.

The instrument’s fault supervision circuitry continuously monitors for failed sensor cell and communication. Our sensor cell operation is continuously supervised 24/7, and when used with distributive control systems or PLCs, the monitor provides immediate fault identification.

Sampling Method
Diffusion Cell
Gases Detected
Hydrogen Sulfide (H2S)
Ethanol (C2H5OH)
Ethane (C2H6)
Ethyl Alcohol (C2H5OH)
Ethylene (C2H4)
Isopropyl alcohol (IPA)
Methyl Alcohol (MeOH)
± 1 % of Reading
Operating Temperature
-32 to +50 ºC
-25 to +122 ºF
3 1/2″ Digit LCD Digital Display

• Refineries

• Natural Gas Operations

• Wastewater Treatment

• Paper Mills

• Oil and Gas

• Iron Smelting

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