Abstract: A method of determining at least one of chemical properties, physical properties and physical states of a gas atmosphere, including the steps of (a) bringing the gas atmosphere into contact with a heatable surface while heating up the heatable surface from a starting temperature to a predetermined higher temperature by the addition of energy thereto over a period of heating time; (b) discontinuing the addition of energy when the predetermined higher temperature is reached; and (c) evaluating heat discharged by the heatable surface under the influence of the gas atmosphere as a function of time to generate a measuring signal. Heating up of the heatable surface by the addition of energy is preferably effected over a period of heating time which is a limited period of heating time, and occurs cyclically at successive intervals in time as a heating cycle.