Method of detecting inhomogeneities in packings

The essence of a method of detecting inhomogeneities in packings, for example in the active-carbon packing loaded into an industrial offgas filter, is that the packed filter is brought to a first temperature level, a fluid which has a temperature level different from the first temperature level is then passed through it and the temperature equalisation in the filter is then monitored using a suitable thermographic recording apparatus. The recording apparatus used may, for example, be an IR camera, inhomogeneous points in the packing being revealed as points having a temperature different from the environment in the image it produces. The inhomogeneities produced can then be quantitatively investigated further in a second stage by means of irradiation.