Abstract: A nuclear detection and measurement system is provided having an ionization chamber with the ionization chamber having enclosed therein a balanced electrometer. The system includes a housing enclosing the ionization chamber, with the housing also enclosing circuitry, a battery, a power source, a microprocessor, and an analog section. The analog section is intermediate and connected by circuitry to the ionization chamber and the microprocessor. The housing has a display panel, and an on/off switch, with the circuitry connecting the power supply to the battery, the on/off switch, the microprocessor, and the display panel. The housing also includes a wireless link, a GPS unit, an RS232 port, a USB port, an alarm, and a battery charger. There is a handle secured to the housing, with the housing having on its exterior a plurality of connections for the RS232 port, the USB port, and the battery charger, and a point of attachment for a bar code reader.

Abstract: A surface radiation detector for sensing low energy ionizing radiation on the surface of an object includes a open window gas proportional counter provided with a compressible skirt surrounding the window in a detection chamber. The compressible skirt is preferably of open cell plastic foam, but may be made from a gas impermeable sheet formed in the shape of an accordion bellows. An open screen of electrically conductive material, attached to said skirt and covering the window, may be placed in direct contact with the surface of an object to be tested. Counter gas flows at a rate into the chamber sufficient to maintain a positive pressure in the chamber relative to the ambient atmosphere. A momentarily actuated valve supplies additional counter gas at a flow rate sufficient to fill said chamber within a short period of time.

Abstract: A method and apparatus for detecting and measuring the areal density of a moving sheet of material having a repetitive pattern by using a scintillation detector operating either in the pulse counting mode or as an analog device includes some means for determining the duration of the repetitive pattern. If the repetition is caused by some characteristic of the production machine, a sensor or pickoff device may be used to synchronize the process; otherwise, the lowest frequency component of a Fourier transform of the variations in areal density is used to determine the repetition interval. Each repetition interval is divided into small measurement increments, and means are employed to average the output of the scintillation detector for each of the corresponding measurement increments in order to provide an accurate and high resolution measurement throughout the repetition interval using an otherwise limited detection device.

Abstract: An alpha particle monitor is disclosed which includes a flow-through linear ionization chamber with means to pass therethrough gas-borne radioactive matter exhibiting alpha decay, such as, radon gas, air-borne plutonium or uranium dust, etc., and an amplifier sensitive to charges on the order of 10.sup.-14 coulombs associated with an alpha emission event. In a preferred form, the amplifier includes a solid state operational amplifier having a stray feedback capacitance sufficiently low to provide, in response to an alpha decay event, an output pulse with a measurable voltage amplitude, e.g., 0.1-1.0 volts, and a feedback resistance sufficiently high to provide the amplifier with a time constant such that the output pulse produced in response to an alpha emission event has a width sufficient to facilitate detection in the presence of noise.