955A Geiger-Mueller Area Monitor

Area monitoring is used for the detection of x-ray or gamma radiation in a selected area. The monitor should be used in any location where personnel may be exposed to an adverse amount of radiation. Applications include nuclear reactors, accelerators, hot cells, irradiators, and any area where radiation sources are handled. These monitors can be used as single channel monitors or grouped together as a multichannel area monitoring system.

The Model 897A Series detectors use a thin walled energy compensated GM tube to detect ionizing radiation. Each Model 897A series detector has a GM tube, a check source and a preamplifier. The check source is a low-level radioactive source actuated by a + 15 VDC meter movement. For positive operation, the check source is electrically driven in both the ON and OFF positions. The preamplifier provides the pulse conditioning and cable driving capability necessary to drive a Model 956A UDR. All Model 897A Series detectors are functionally identical. They differ only in housing material, tube type and range. The Model 897A series detectors operate in the voltage range between 500 to 650 VDC. The Model 897A Series detector is designed to operate with the Model 956A UDR or with other readouts. Each detector measures a five decade range. Three measurement ranges are available: low, medium and high. The low range covers 10^-2 to 10³ mR/h, the medium covers 10^-1 to 10⁴ mR/h, and the high covers 10⁰ to 10⁵ mR/h. The Model 897A Series detector may also be used with the Model 960 Digital Radiation Monitoring System (DRMS) equipment or the Model 856 Analog Readout.