MSA Safety Altair - CO [30/60 ppm] Gas detector The ALTAIR is a reliable, high performance, single gas component detection instrument with optional sensors (H2S, CO, and O2). It is guaranteed to be maintenance free for two years or 1080 alarm minutes. The instrument is operational until the end of the batteries' lifetime, i.e. more than two years under normal conditions. No calibration, replacement of sensors or batteries is required. The ALTAIR instruments for measuring carbon monoxide and hydrogen sulphide use the patented MSA button sensors, while the version for measuring oxygen uses a fast-responding 20 series sensor. Thanks to the proven clip-on design typical of the range, ALTAIR instruments can be used almost anywhere.