Automatic radon counter for continual unattended operation

An improved portable radon sampler is described which is capable of sampling and measuring atmospheric radon concentrations at repetition rates of up to five samples per hour, with sensitivities down to 0.1 pCi m(-3). The sampler and sensor can be located remotely from the counter and readout devices. The digital output of the unit is available to a printer, a digital recorder, and a computer, and a rate-meter type output is observable in real time and recorded on a strip chart.. This instrument has operated throughout full gale conditions at sea and for up to two weeks without maintenance.