ST-48 Carbon Monoxide (CO) Gas Monitor

ST-48 Carbon Monoxide (CO) Gas Monitor

Item #: 95107


Product Summary

The carbon monoxide gas monitor is used for safety in laboratories, or facilities requiring the safety detection of CO. The CO gas detector comes with 2 alarm relays with a signal to the horn/strobe, building systems, etc. There are built-in visual alarms with bright LEDs, a 4-20mA analog output, and 24/7 supervised electronics that continuously check the sensor.


  • CO, IPA, H2, H2S, and Other Toxic Gases
  • Dual Sensor Capability
  • Non-Intrusive One-man Calibration
  • Ex Proof Enclosure Div 1 & 2, Group 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 instrument’s fault supervision circuitry continuously monitors for failed sensor cell and communication line breaks. Plus sensor cell operation is continuously supervised 24/7 and when used in conjunction with distributive control systems or PLCs, provides immediate fault identification for a disconnected sensor cell.

The AirCheck Ex is housed in a NEMA 7 explosion-proof enclosure and is available for Carbon Monoxide, IPA, H2, H2S, and other toxic gases. Capable of monitoring ppm levels of toxic gas or % LEL levels of combustible gases, the AirCheck Ex is a perfect monitoring solution for providing worker protection in chemical plants, refineries, and other areas requiring hazardous classifications.

Sampling Method Diffusion
Gases Detected Carbon Monoxide (CO)
Ethyl Alcohol (C2H5OH)
Hydrogen Sulfide (H2S)
Isopropyl alcohol (IPA)
Methyl Alcohol (MeOH)
Range 0-100% ppm
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

One or Two Gas Monitoring
The PureAire AirCheck Ex electronics is capable of monitoring one gas or two different individual gases simultaneously with one transmitter. The Dual Sensor Configuration displays two-gas readings and outputs 4-20 mA outputs for each gas to remote controllers.

ST-48 Carbon Monoxide Gas Monitor Literature

St-48 Manual

Air Check Ex Dual Gas with Relays 

Gases Detected with PureAire Monitors



Remote Digital Display LEL 99185

Remote Digital Display LEL 99185


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