Combustible/Toxic Gas Monitor

Combustible/Toxic Gas Monitor

Item #: ST-48


Product Summary

PureAire’s Combustible/Toxic Gas Detectors are ideal for facilities that require continuous monitoring of toxic or combustible gases in hazardous areas. The enclosure is specifically designed to prevent an explosion. The monitor is well-suited for environments such as refineries, wastewater treatment, parking garages, laboratories, pharmaceutical, research and development, natural gas locations, the oil and gas industry, and any locations where toxic or combustible gases are present.


  • Dual Sensor Capability
  • Non-Intrusive One-man Calibration
  • Ex Proof Enclosure Class 1, Div 1 & 2, Groups A, B, C, & D
  • Local Digital Display with Bargraph & Trending
  • User Adjustable Dual Alarm Relays
  • 4-20 mA Analog Output
  • RS-485 Modbus Optional
  • NRTL CSA Approvals, ATEX Optional

The Combustible/Toxic Gas Detector’s instrument fault supervision circuitry continuously monitors for failed sensor cells and communication line breaks. Plus, sensor cell operation is continuously supervised 24/7, and when used in conjunction with distributive control systems or PLCs, it provides immediate fault identification for a disconnected sensor cell.

PureAire’s Combustible/Toxic Gas Detector is housed in a NEMA 7 explosion-proof enclosure suitable for Class 1, Division 1 and 2, Groups A, B, C, and D. The gas detector can be used to detect Carbon Monoxide, IPA, Hydrogen, Hydrogen Sulfide, Ethanol, Propane, and other toxic gases. Capable of monitoring ppm levels of toxic gas or % LEL levels of combustible gases, it is a perfect monitoring solution for providing worker protection in chemical plants, refineries, and other areas requiring hazardous classifications.

Sampling Method Diffusion
Gases Detected¹ Carbon Monoxide (CO)
Ethyl Acetate (C4H8O2)
Hydrogen Sulfide (H2S)
Isopropyl alcohol (IPA)
Methane (CH4)
Accuracy ± 10 % of Reading
Operating Temperature -40 to +50 ºC
-40 to +122 ºF
Display 68 x 128 pix LCD Displays 30-min Trend, Bargraph & 0.6″ Concentration Data
Sensor Type Disposable Electrochemical or LEL Catalytic Bead
Sensor Life 2 to 5 years under Normal Conditions
Signal Outputs 4-20 mA analog output
Power Requirements 24 VDC
95 mA
Width 5.12 in
130.05 mm
Height 5.0 in
127 mm
Depth 8.0 in
203.2 mm
Weight 4.7 lbs
2.1 kg
Enclosure Stainless Steel
Optional Extras Alarm Output: 3ea. Alarm Relays: Low and High-Level Gas Alarm and System Fault
Signal Output: RS-485 Modbus Digital Communications
Country of Origin USA
Harmonized Tariff Code 8531.10.0045

1 Contact PureAire Monitoring for additional gases

One or Two Gas Monitoring

PureAire’s Combustible/Toxic Gas Detector electronics can monitor one gas or two different individual gases simultaneously with one transmitter. The Dual Sensor Configuration displays two gas readings and outputs 4-20 mA for each gas to remote controllers.


Combustible/Toxic Gas Monitor Literature

Combustible/Toxic Gas Monitor Manual

Air Check Ex Dual Gas with Relays 

Gases Detected with PureAire Monitors

Flameproof / Hazardous Location Strobe with optional Horn

Remote Digital Display LEL 99185

99185 Remote Display LEL


8-Channel Controller for Oxygen, Carbon Dioxide, or Toxic/Combustible Gas Monitors