Fast measurement of the local EEC/PAEC

During site inspections in mines, it is required to take air samples sequentially at different locations. The result should be present as soon as possible. Due to the radon decay chain, the response time in case of continuous sampling is too large for such measurements.

A simple but quite accurate approach offers the so-called Markov method. The measurement starts with a five-minute pump interval to take the air sample. After that, the instrument determines the gross-alpha activity within a counting interval. The offset time and the duration of the counting period is well-defined in that way that the measured activity is proportional to the concentration of radon daughter products.

It is presumed that prior to each measurement a fresh filter was inserted. Loaded filters can be re-used after the complete decay of the collected activity (about 3 hours).

This sampling method is implemented in the RPM 2200, EQF 3200, EQF 3220 and poCAMon. The measurement will be finished after 20 minutes, pump interval included. The instrument can be relocated as soon as the pump has stopped.