INFRARED ANALYZERS BASIC INFORMATION AND TUTORIALS

What is an Infrared Analyzer?

Description and Applications.
The infrared analyzer is used as a screening tool for a number of gases and vapors and is presently the recommended screening method for substances with no feasible sampling and analytical method.

These analyzers are often factory-programmed to measure many gases and are also user-programmable to measure other gases. A microprocessor automatically controls the spectrometer, averages the measurement signal, and calculates absorbance values.

Analysis results can be displayed either in parts per million (ppm) or absorbance units (AU). The variable path-length gas cell gives the analyzer the capability of measuring concentration levels from below 1 ppm up to percent levels.

Some typical screening applications are:

• Carbon monoxide and carbon dioxide, especially useful for indoor air assessments;
• Anesthetic gases including, e.g., nitrous oxide, halothane, enflurane, penthrane, and isoflurane;
• Ethylene oxide; and
• Fumigants including e.g. ethylene dibromide, chloropicrin, and methyl bromide.

Calibration.
The analyzer and any strip-chart recorder should be calibrated before and after each use in accordance with the manufacturer's instructions.

Special Considerations. 
The infrared analyzer may be only semispecific for sampling some gases and vapors because of interference by other chemicals with similar absorption wavelengths.

Maintenance. 
No field maintenance of this device should be attempted except items specifically detailed in the instruction book such as filter replacements and battery charging.