ANALOGUE ISOLATOR IS SIMPLE AND RELIABLE.

Analogue isolation must be incorporated in many instrumentation systems to eliminate any galvanic connection between sub units. For example, environmental sensors, such as pH electrodes, might have a direct galvanic connection to ″ground″ via the tested solution. Consequently, any other connection to ″ground″ might cause an erroneous reading due to partial shorting of the electrode's signal. Therefore, in such applications, the electronic circuitry must be ″floating″ with respect to ground. This could cause difficulties when the output signals must be fed to other units, such as a data processing system, which are grounded. The problem could be overcome by using an isolation amplifier which provides complete galvanic isolation between input and output sections. A simple and inexpensive circuit that was found very effective in such applications is presented.