TEST CHAMBER

The invention relates to a test chamber (10) for conditioning air, comprising a test space (12) for holding test material, which test space, with respect to surroundings, can be closed off and is temperature-isolated, and comprising a temperature-control device (11) for the temperature control of the test space. A temperature in a temperature range of -80 DEG C to +180 DEG C, preferably -100 DEG Cto +200 DEG C, can be formed within the test space by means of the temperature-control device. The temperature-control device has a cooling device (16). Said cooling device has a cooling circuit (17)having a refrigerant, a heat exchanger (18), which is arranged in the test space, a compressor (19), a condenser (20), and an expansion element (21). The refrigerant is a nearly azeotropic and/or zeotropic refrigerant mixture of a mass fraction of carbon dioxide and a mass fraction of at least one of the components ethane, ethylene, hexafluoroethane, pentafluoroethane, monofluoroethane, 1,1-difluoroethylene, fluoromethane