Patent ID: 9411056
Filing Date: 2016-08-09
CPC Classification: G01T

Claim Text:
1. A radiation monitor including: an ionization chamber for detecting radiation that passes into the ionization chamber, the ionization chamber generating a current flow in response to the detected radiation; and an electrometer electrically connected to the ionization chamber for measuring the current flow generated by the ionization chamber, the electrometer including an amplifier having at least one input connected to the ionization chamber and an output, a first capacitor having first and second terminals respectively connected to the at least one input and the output such that the first capacitor is directly connected between the at least one input and the output, a second capacitor selectively connectable between the at least one input and the output, a plurality of switches operable for selectively connecting the second capacitor between the at least one input and the output and for selectivity connecting the at least one input and the output directly together and to ground, wherein the electrometer is configured, via operation of the plurality of switches, to be operable in a plurality of modes based on a magnitude of the current flow generated by the ionization chamber, the second capacitor having first and second terminals with the second terminal of the second capacitor being connected to the output, the plurality of switches includes a first switch connected between the at least one input and the first terminal of the second capacitor with the first terminal of the second capacitor being connected to the at least one input when the first switch is closed, a second switch connected between the first terminal of the second capacitor and ground with the first terminal of the second capacitor being connected to ground when the second switch is closed, and a third switch connected parallel to the second capacitor between the first and second terminals of the second capacitor with the first and second terminals of the second capacitor being connected when the third switch is closed.