New current measuring technique for electrical aerosol analyzers

A new measuring technique for electrical aerosol analyzers has been developed. The special feature of the present method is the current measuring technique which makes it possible to continuously measure the electric current collected by the mobility analyzer. The experiments were carried out with a simple zeroth-order analyzer. The results of these experiments indicate that the collecting voltage of the analyzer can be varied in the range of 0–5000 V and simultaneously it is possible to measure the collected electric currents down to 0.01 pA. The measuring system also consists of a conventional current sensor realized by means of a filter charge collector. Thus, the measuring system consists of two current sensors: one for particles penetrating the mobility analyzer and another for particles collected by it. The possibility to continuously measure both currents is of great importance when measurements are carried out in rapidly varying conditions