Performance of x-ray measurement instruments when subjected to environmental level rf fields

The purpose of this work was not to quantitatively examine x-ray measurement-instrument performance in an rf field but rather to see if performance is altered when an rf field is applied. The results of this study show that when ionizing radiation measurements must be made in areas where rf fields can be expected to occur (i.e., hospitals, airports, and so forth), extreme care in the use of ionization chamber type instruments must be exercised. The results of the present experiment indicate that x-ray exposure and/or exposure rate meters of the ionization chamber type, though superior for precise radiation measurement, are susceptible to environmental level rf fields. Since these instruments must be employed for most measurement situations, it is imperative that rf fields be removed from the environment of the x-ray meter or that the x-ray meter be properly shielded from rf interference. It is obvious that if levels of rf radiation at locations such as hospitals or airports are high enough to disrupt the true response of x-ray measuring devices used at these locations, then the indicated x-ray exposures are invalid. Presently, BRH is investigation methods of rf shielding modifications of existing x-ray detection/measurement equipment