A differential electrometer with dynamic gain for pulsed amperometric measurement

An electrometer is described which will measure the transient currents in an electrochemical cell activated by a pulsed polarization potential. This electrometer consists of dual current to voltage transducer stages allowing differential current measurement. Each stage has dynamic stepped-up gain capability which can be varied under digital control. The dynamic gain enables maximum sensitivity of measurement while preventing saturation of the amplifiers by large magnitude current spikes present at the initial application of the polarization potential. The electrometer can measure the current passing through an unshielded electrochemical cell with an accuracy of ±10pA. The electrometer does not affect nor interfere with the electrodes performance. Also, the instrument does not influence the electrochemical processes. This electrometer has application in pulse polarography and other amperometric type electrochemical measurements.