Measurement of short lived radon daughters in Polish mines

Obligatory measurements of the potential alpha energy concentration of short-lived radon daughters have been performed in the Polish underground mines since 1989. In consideration of economical aspects, it is attempted from the very beginning to combine it with measurements of the dust concentration. Therefore the developed measuring units were an integral part of the dust samplers complying with the requirements of the State Mining Authority for application in underground mines. This way the developed devices could fulfil two measurement tasks simultaneously: measurement of the dust concentration and potential alpha energy concentration of short-lived radon daughters. The new device based on the thermoluminescent detector is able to operate with the SKC universal pumps equipped with a cyclone, making it possible to operate constantly for one working day. The lower limit of detection was about 0.04 μJ/m3 at a 95% confidence level and 1 h pumping time. (author)