US 3,984,690 A · Circuitry for use with an ionizing-radiation detector

Abstract

An improved system of circuitry for use in combination with an ionizing-radiation detector over a wide range of radiation levels includes a current-to-frequency converter together with a digital data processor for respectively producing and measuring a pulse repetition frequency which is proportional to the output current of the ionizing-radiation detector, a dc-to-dc converter for providing closely regulated operating voltages from a rechargeable battery and a bias supply for providing high voltage to the ionization chamber. The ionizing-radiation detector operating as a part of this system produces a signal responsive to the level of ionizing radiation in the vicinity of the detector, and this signal is converted into a pulse frequency which will vary in direct proportion to such level of ionizing-radiation. The data processor, by counting the number of pulses from the converter over a selected integration interval, provides a digital indication of radiation dose rate, and by accumulating the total of all such pulses provides a digital indication of total integrated dose. Ordinary frequency-to-voltage conversion devices or digital display techniques can be used as a means for providing audible and visible indications of dose and dose-rate levels.

Claims12

Dependent claims

For use in combination with a radiation detector producing a current output signal corresponding to the amount of radiation incident on the detector, an improved digitizing circuits for providing a digital representation of radiation level over a wide range, the improved circuit comprising:

a. current-to-frequency converter means operably associated with the radiation detector for producing a pulse-repetition frequency representative of the output current of the detector;
and
b. data-processing means operably associated with the current-to-frequency converter means for measuring the pulse-repetition frequency, and to provide a digital representation of radiation level by counting pulses over a selected time interval.

For use in combination with a radiation detector which produces a current output signal corresponding to the level of radiation incident on the detector, an improved digitizing circuit for providing a digital representation of radiation level over a wide range, the improved circuit comprising:

a. a capacitive-feedback current-to-frequency converter operably associated with the radiation detector for producing a pulse repetition frequency representative of the output current of the ionizing-radiation detector;
b. first pulse counting means operably associated with the current-to-frequency converter for measuring the pulse-repetition frequency by counting the number of pulses over a known time interval;
c. time-gate logic means operably associated with the current-to-frequency converter and the first pulse counting means for selecting an integration interval for operation of the pulse counter and for varying the reset period of the converter to reduce its dynamic range in charge;
d. display means for providing a digital signal representative of radiation level;
and
e. power supply means for providing proper operating voltages to the circuit and to the ionization chamber.

3 more elements

Dependencies are inferred from the claim text.

Circuitry for use with an ionizing-radiation detector

Life of this patent

Circuitry for use with an ionizing-radiation detector

Life of this patent

Abstract

Claims12