The Berthold Technologies 9100D moving filter monitor collects and measures air from the environment or stacks and ducts for the presence of Alpha and Beta particulates. The design integrates a sampling head with detector(s), a high flow rate pump unit, the filter-tape control and the counting electronics in a standard 19” enclosure.

An S-class glass fiber filter-tape collects the sample air particulates.

This filter-tape advances at a programmable continuous or sequential speed eliminating the need for frequent filter replacement due to dust loading.

A prompt Plastic scintillation detector allows the measurement of both Alpha and Beta particulates in real time. An optional delayed detector measures the sampled air 5 days after collection to eliminate all natural activity through decay from the sample.

The prompt detector is installed above the dust collection area at close distance to the filter, and delivers optimal Alpha & Beta counting performance.

Radon progeny influence is strongly reduced from the real time gross Alpha Beta activity using either Pseudo-coincidence gating or Beta/Alpha ratio compensation methods .

Downstream of the filter a silent, maintenance free pump unit ensures a stable flow rate of 20-25 m3/h.

In the environmental monitoring version a 6-Channel electronics processes the detector signals. This electronics allows the user to measure the presence of both natural and artificial radioactive aerosols as well as the ambient dose rate and to trigger alarms above certain levels. Alternatively the monitor can be supplied with a 10-Channel electronics designed for Stack or release rate monitoring applications.

The healthy status of the overall system is continuously monitored.

Also available for environmental monitoring applications is a combined Particulates and Iodine-131 monitor. Furthermore a number of customized versions were built for applications like incinerator activity monitoring, nuclear fuel reprocessing off-gas monitoring, uranium mine monitoring, and many more.

Alpha-Beta particulates monitoring in low to medium intensity gamma fields.

Environmental, stack- and duct monitoring requiring long maintenance intervals even when the air contains high or very high dust concentrations, preventing the use of fixed filters and high flow rates.