This standard specifies the definition, influence, performance parameters, test items and methods of infrared gas analyzers. This standard applies to non-dispersive infrared gas analyzers that continuously measure one or more gas components in ambient air or gases entering ambient air, that is, a complete set of analysis units including optical, mechanical, electrical and electronic components as an overall analysis unit. Instruments and supporting regulated power supplies. This standard does not apply to sample processing systems or recorders, analog-to-digital converters, data collection system accessories, etc. used in conjunction with analyzers.