The RDS Low Background Alpha Counter (LBAC) is a small, battery-operated alpha counter for the alpha counting of 25 mm and/or 37 mm air-sampler filter material. Typical alpha-counter background is below 0.001 c/s. The counter detection efficiency and the background count rate are programmed into the microcontroller memory. Alpha counting can be carried out in fixed counting windows (100 s, 1 000 s, 10 000 s) or in a manual counting mode.
When the counting is finished, the total count is displayed on the bottom line of the LCD; the total alpha activity on the filter is momentarily displayed when the “N” switch is pressed. The total alpha activity is calculated considering the total count rate, the background count rate, and the counter detection efficiency.