Hand and shoe monitor using air ionization probes

Claim 2

A radiation monitor, comprising: a plurality of air ionization probes, a chambered grill-type probe body, one of each of such probes being mounted in each chamber of said probe body such that the grill work of said body provides structural strength for protecting said probes from force applied to said body during a radiation monitoring event, a thin conductive window covering one open side of the chambers, circuit means responsive to radiation events detected by said probes to develop an output signal corresponding thereto, and a grill matched to the grill work of said probe body and coupled to said body so that said window is between said grill and said body.

Claim 3

The monitor of claim 1 wherein said circuit means includes a conventional amplifier to which the output of said probes is applied, a resistor of value R 1 and a capacitance of value C 1 coupled in parallel with said conventional amplifier, a resistor of value R 2 and a capacitance of value C 2 coupled in parallel with each other and in series with said conventional amplifier with R 1 C 1 =R 2 C 2 , a first current mode amplifier with one input thereof coupled in series with said R 2 resistor and said C 2 capacitance, a resistance of value R 3 coupled between the other input of said first current mode amplifier and the output of said conventional amplifier, a resistance of value R 4 coupled in parallel with said first current mode amplifier, so that the output of said first current mode amplifier corresponds to the instantaneous differential current from said probes with respect to an average background level, and means coupled to said first current mode amplifier responsive to particular changes in the output of said first current mode amplifier to generate an alarm signal.

Claim 4

The monitor of claim 2 wherein said means coupled to said first current mode amplifier includes a second current mode amplifier to one input of which is applied the output of said first current mode amplifier, a diode and a capacitance of value C 3 coupled in series with the output of said second amplifier so that C 3 is charged with decreases in the output of said first current mode amplifier and discharges slowly through a resistance of value R 5 and said capacitance of value C3 with increases in the output of said first current mode amplifier, and a comparator which generates an alarm signal with the voltage across C 3 equal to or greater than a predetermined value.