A qualitative study of radio-frequency interference in radiac-telemetry systems

In: http://hdl.handle.net/2027/mdp.39015095219054

Abstract

These tests, which showed that significant errors can result from RFI, demonstrated the need for system designs which minimize radio-frequency (r.f.) coupling to the high impedance elements of the radiation detector and circuitry. RFI in the radiation recorder tested caused an increase in the recycling period of 20 percent or more under some conditions. This increase was attributed to the recharging of the radiation detector by the r.f. through the diode action of the electrometer tube. Also, it was found that the effect of bandwidth limitation on the transmitted pulse output of the recorder was small and that the system accuracy was not significantly lowered. However, system noise reduced reliability at very low pulse repetition rates. The test results showed that potential RFI problems exist in radiac-telemetry systems. Most of these problems can be met satisfactorily through the use of common r.f. elimination techniques. ; With the need for radiological data for military purposes and public safety, radio telemetry may be used extensively in the transmission of radiological information. The use of radio telemetry in nuclear radiation measuring systems introduces potential radio-frequency interference (RFI) problems in the detector elements of the system, due to the telemetry transmitter, and in the reception process, due to noise. Also, data accuracy may be reduced by the bandwidth limitation of the telemetry system. In an effort to better understand the effects of RFI and bandwidth limitation on data accuracy and reliability, a number of qualitative tests were made with an existing recycling electrometer type of radiation recorder coupled to a standard telemetry system. ; "8 February 1962." ; Ntis: ad273452. ; Accession No.: 57315. ; Includes bibliographical references (pages 7-8). ; These tests, which showed that significant errors can result from RFI, demonstrated the need for system designs which minimize radio-frequency (r.f.) coupling to the high impedance elements of the radiation detector and circuitry. RFI in the radiation recorder tested caused an increase in the recycling period of 20 percent or more under some conditions. This increase was attributed to the recharging of the radiation detector by the r.f. through the diode action of the electrometer tube. Also, it was found that the effect of bandwidth limitation on the transmitted pulse output of the recorder was small and that the system accuracy was not significantly lowered. However, system noise reduced reliability at very low pulse repetition rates. The test results showed that potential RFI problems exist in radiac-telemetry systems. Most of these problems can be met satisfactorily through the use of common r.f. elimination techniques. ; With the need for radiological data for military purposes and public safety, radio telemetry may be used extensively in the transmission of radiological information. The use of radio telemetry in nuclear radiation measuring systems introduces potential radio-frequency interference (RFI) problems in the detector elements of the system, due to the telemetry transmitter, and in the reception process, due to noise. Also, data accuracy may be reduced by the bandwidth limitation of the telemetry system. In an effort to better understand the effects of RFI and bandwidth limitation on data accuracy and reliability, a number of qualitative tests were made with an existing recycling electrometer type of radiation recorder coupled to a standard telemetry system. ; Mode of access: Internet.