Automatic measuring device for beta dosimetry

A measuring device is described which enables dose rates in soft tissue produced by beta radiation to be measured. The main components of this device are an extrapolation chamber and a sensitive current-measuring system. The current of the extrapolation chamber is measured automatically for preselected chamber depths together with the temperature, pressure and relative humidity of the air of the collecting volume. An IBM-compatible Zenith-AT computer with a memory of 640 kByte and a 80 MByte hard disk controls the whole measuring procedure and evaluates the data by means of self-developed Turbo-Pascal programs. The components of the measuring device, their calibration, several measuring programs and preparatory measurements for the operation of the device are described in detail in this report. The capacity of the device is demonstrated with examples of experimental data on an extrapolation curve and a depth dose curve. The report is supplemented by a number of details in the appendix. Besides wiring diagrams of self-developed electronis circuits formulas for calculating the capacity of a guard ring capacitor and the air density, for example, are also included. (orig.)