The hypoxia monitor, Model TX-1100DRA 99016, is ideal for facilities using inert gases such as nitrogen, CO2, helium and argon. The monitor is ideal for use in confined Spaces, cryogenic facilities and freezers. The monitor will remain accurate at temperatures as low as -40C. PureAire's durable, lossless, long-life zirconia sensors last more than 10 years under normal conditions without replacement.