Abstract: A method for the automatic reading of the radiation dose of a portable dosimeter with an ionization chamber provided with a capacitor C.sub.1, and a device for carrying out said method, said device comprising means for measuring the value of the ionization chamber charge at each reading operation and means for storing the value of the charge of said ionization chamber, as well as means for calculating the radiation dose D at any moment from one of the stored values and from the value of the charge of said chamber at said moment.

Abstract: When subjected to radiation overload existing Geiger-Mueller counters may give an erroneously low reading, resulting in possible hazard to personnel. The instant invention discloses simple and inexpensive apparatus to remedy this dangerous shortcoming. Depending on the geometry of the detector tube, two possible failure modes have been identified, and circuitry is disclosed to detect the existence of these respective failure modes. The disclosed apparatus indicates the absence of an overload condition, in addition to signaling, by both visible and audible means, the existence of excessive radiation that might result in erroneously low reading of the Geiger-Mueller counter.

Abstract: An exposure detecting device comprising a radiation detector means providing an output signal responsive to the intensity of received ultraviolet radiation, a storage means receiving the output signal of said detector means and providing an output signal which increases as a function of the signal received and its duration, and decreases in the absence of a received signal as a predetermined function of time. A sensitivity control means provides a reference signal, and comparing means receives the output signal of said storage means and the reference signal of said sensitivity control means and delivers an output signal when the storage means output signal exceeds a predetermined value with respect to the reference signal. Alarm means is activated upon receiving an output signal from said comparing means providing an alarm.

Abstract: A CT scanner has an outer circular array of stationary radiation detectors for an inner concentrically revolving source of radiation emitted in a fan pattern subtending a number of the detectors. A number of analog signal processing channels equal to the maximum number of subtended detectors at any given time is automatically connected via switching circuitry to receive the outputs of only the detectors within the fan pattern.

Abstract: A position-sensitive proportional counter circuit is provided which allows the use of a conventional (low-resistance, metal-wire anode) proportional counter for spatial resolution of an ionizing event along the anode of the counter. A pair of specially designed active-capacitance preamplifiers are used to terminate the anode ends wherein the anode is treated as an RC line. The preamplifiers act as stabilized active capacitance loads and each is composed of a series-feedback, low-noise amplifier, a unity-gain, shunt-feedback amplifier whose output is connected through a feedback capacitor to the series-feedback amplifier input. The stabilized capacitance loading of the anode allows distributed RC-line position encoding and subsequent time difference decoding by sensing the difference in rise times of pulses at the anode ends where the difference is primarily in response to the distributed capacitance along the anode.

Abstract: Measuring channels with ionization detectors as primary input are supervised by monitoring any imbalance between AC and DC components of the measuring currents, primarily to detect insulation failure of the connecting cable on account of heavy radiation and thermal losses. Detection of the imbalance is independent from radiation changes to be measured.

Abstract: A metering circuit for a condenser ionization chamber is disclosed for simultaneously recharging the ionization chamber and reading out the amount of charge required to recharge the chamber. During the recharging process, the amount of charge necessary to recharge the ionization chamber capacitor is placed on an integrating capacitor in the metering apparatus. The resultant voltage across the integrating capacitor is a measure of the radiation to which the ionization chamber was exposed.