Carbon Monoxide Monitor

Measure the amount of carbon monoxide (CO) in ambient air with the Thermo Scientific™ Model 48i CO Analyzer. The gas filter correlation technique as utilized by the Model 48i gas filter correlation analyzer offers over 30 years of field-proven performance in providing accurate and reliable readings.

Carbon monoxide (CO) is a poisonous, colorless, odorless gas. Workers may be exposed to harmful levels of CO in a variety of industrial environments employing gasoline-powered equipment or where other carbon-containing materials such as natural gas, kerosene, oil, propane, coal, or wood are burned. These include boiler rooms, breweries, warehouses, petroleum refineries, pulp and paper production, and steel production. Internal combustion engines are one of the most common sources of exposure in the workplace; forges, blast furnaces and coke ovens also produce CO.


The Model 48i is based on the principle that carbon monoxide (CO) absorbs infrared radiation at a wavelength of 4.6 microns. Because infrared absorption is a nonlinear measurement technique, it is necessary for the instrument electronics to transform the basic analyzer signal into a linear output. The 48i uses an exact calibration curve to accurately linearize the instrument output over any range up to a concentration of 10,000ppm.

Key Features:

  • Gas filter correlation technology
  • Linearity through all ranges
  • Measures concentrations up to 10,000ppm
  • Standard dual range and auto ranges
  • Temperature and pressure correction

iSeries Advantage:

  • Ethernet connectivity for efficient remote access
  • Enhanced user interface with one button programming and large display screen
  • Flash memory for increased data storage and user downloadable software
  • Enhanced electronics design optimizes product commonality
  • Improved layout for easier accessibility to components

The Mode 48i CO Analyzer is also available with an oxygen sensor module.

The Model 48i with Oxygen uses paramagnetic sensor technology to extend CO measurement capabilities, reading and reporting the concentration of oxygen in the sample stream up to 100%. Additionally, programming allows the user to correct the CO reading for the amount of oxygen in the sample.

Detectable Analytes Carbon Monoxide
Flow Rate 0.5 to 2 L/min.
Inputs 16 Digital Inputs (Standard), 8 0 to 10 VDC Analog Inputs (Optional)
Linearity 2% full scale
Response Time 60 sec. (30 sec. average time)
Span Drift ±1% full scale
Temperature (English) Operating 32°F to 113°F
Temperature (Metric) Operating 0°C to 45°C
Zero Noise 2 ppb RMS
Certifications/Compliance ETL, CSA, UL, CE; U.S. EPA, European (TUV), MCERTS, UKCA
Depth (English) 23 in.
Depth (Metric) 584 mm
Description 48i CO Analyzer
Detection Limit 0.04 ppm
Height (English) 8.62 in.
Height (Metric) 219 mm
Measurement Range Preset: 0 to 50, 100, 200, 500, 1000, 2000, 5000, 10000 and 20000 ppm; 0 to 50, 100, 200, 500, 1000, 2000, 5000, 10000 and 20000 mg/m3; Custom: 0 to 50 to 20000 ppm; 0 to 50 to 20000 mg/m3
Outputs Selectable Voltage, RS232/RS485, TCP/IP, 10 Status Relays, and Power Fail Indication (standard); 0 to 20 or 4 to 20mA Isolated Current Outout (optional)
Precision ±0.1 ppm
Voltage 100/115/220/240 V
Weight (English) 49 lb.
Weight (Metric) 22.2 kg
Width (English) 16.75 in.
Width (Metric) 425 mm
Zero Drift <4ppm
Unit Size Each