Method for measuring filling level of goods in container in e.g. chemical industry, involves diagnosing composition of unknown gas deviating from reference gas, when comparison of reference and auxiliary functions provides marked deviation

摘要

The method involves receiving a reflection signal (R) after elapse of a signal propagation delay. A reference function (Fr) reproducing amplitude characteristics of the signal is derived, when reference gas i.e. air, is present in goods (1) to be filled. An auxiliary function (Fx) reproducing the amplitude characteristics is derived, when unknown gas e.g. ammonia, is present above the goods. The functions are compared with each other. Composition of the unknown gas deviating from the reference gas is diagnosed, when the comparison provides marked deviation (delta x) between the functions.