The Model 500 Nuclear Belt Scale /Density Meter is a nuclear gauging device which uses a sealed radioactive source to measure material weight as it travels on a conveyor belt.
The measurement principle is based on the attenuation characteristics of gamma energy as a function of density. The instrument does not come into contact with the conveyor or the material being conveyed, and bolts to the existing conveyor structure.
The measuring portion of the device, which consists of a source holder and detector assembly, is mounted across a conveyor belt on the existing belt structure. The source assembly contains a single gamma source, and collimates a radiation beam down through the material to be measured. A gamma radiation detector is mounted beneath the belt and measures the gamma attenuation caused by the material on the belt above. The detector is connected to an electronics enclosure housing an industrial computer which processes the detector signals and displays the measured results to the operator.
The instrument generates weight measurements every three seconds and averages the readings to produce values every minute. These values are made available to plant control systems through direct access to the system database or through analog outputs provided with the system.