[Microwave radiation sources requiring periodic or sporadic hygienic control]

Throughout 1972--1978 measurements of dissipated microwave radiation in the environment of about 600 microwave apparatus of various types were taken. In the environment of the apparatus dissipated microwave radiation was found of values of the safety, dangerous, warning and intermediate zones, respectively. In the hitherto taken measurements many microwave devices have been observed, in whose environment no dissipated microwave radiation but low values in the safety zone have been found. These are e.g. such devices as sets of microwave laboratory systems of a very low power, microwave block in EPR spectrometers and NEC radio link transmitters. Our investigations indicate that for those devices sporadic hygienic control of electromagnetic field would be sufficient. Different types of microwave sources categorized into two groups according to the values of power density of dissipated microwave radiation near those sources have been presented.