Sierra Monitor Corporation offers the 4501-04, 2-Wire Carbon Monoxide Gas Sensor Module.  Two-wire, loop powered gas detectors provide the user with lower cost and easier installation and maintenance.  This eliminates the need for separate power runs and associated power distribution and circuit protection for each device.

Carbon monoxide is a dangerous workplace hazard in many industrial plant environments.  This toxic, colorless, odorless gas can be produced as the result of combustion engines, boilers, forklifts and more.  Example industries include wastewater treatment, oil and gas, boiler rooms, parking garages, steel plants and more.

The new 2-wire CO Gas Sensor provides features not found in similar products, including: 
- Low maintenance costs due to 180 day (six-month) calibration interval
- Low installation costs due to 4-20 mA 2-wire loop-powered design
- User-friendly operator interface with integral scrolling menu-driven LCD display for easy access to gas status, calibration instructions, adjustment of ranges and outputs and diagnostic information.
-  Fastest response time, highest accuracy, and specifications unmatched in the industry.
-  Durability of a stainless steel transmitter and sensor enclosure
-  Application adaptability with variable range selection and mounting configuration.
- Non-intrusive calibration to enable calibration without declassifying the area
- Common signal output of 4-20 mA