The FD223a is a dual differential, high impedance amplifier/electrometer designed specifically for electrochemical measurements using ion specific (K+, Na+, Cl-, etc.) or pH electrodes. The instrument is very stable, drift free, and features a built in provision for measuring and adjusting input leakage current. DC levels may be independently adjusted for each probe channel.
The ability to locate the sensing probes directly at the measurement site overcomes the noise introduced by the long cables usually needed to bring the measured potential to the instrument. Signal-driven guards at the probe input maintains the specified high resistance and reduces the stray capacitance of the probes. Careful design, coupled with quality component selection, particularly in the headstage, results in an excellent amplifier with low noise and wide bandwidth.
Probe Test Port
The amplifier features a probe test port that permits testing of the electrode test feature and setting of the probe leakage current.