MEASURING DEVICE, FOR EXAMPLE AN ELECTRIC ENERGY METER, ADAPTED FOR AVOIDING FRAUDULENT USE THROUGH AN APPLICATION OF AN INTERFERING MAGNETIC FIELD

摘要

In a measuring device, adapted for avoiding fraudulent use through an application of an interefering magnetic field, a magnetic field density threshold detector (1a', 1a'') is constructed as a release (1a', 1a'') made as a ferromagnetic flexible strip which is fixed at one end and which, influenced by the magnetic field with a field density above threshold field density, is drawn away from below an end of an indicating drop strip (3a), which is rotatingly fastened at its other end and which indicates whether magnetic field with a field density above threshold field density has been detected.In preferred embodiments of the measuring device it is possible to prove beyond ambiguity whether its interior was exposed to an interfering magnetic field with such field density that the functioning of the measuring device was incorrect or disturbed.