The BCDT128 is a 4-wire transmitter designed for any type of conductivity input and process signal output. The BCDT128 suits a wide range of conductivity measurement applications using suitable probes. Temperature compensation is also available as an option using probes with a built-in NTC thermistor or any other suitable compensation element. Excitation to the probe is via a low level AC voltage with short circuit protection to maximise the life of the probe. Final calibration is trimmed using the front accessible ‘offs’ and ‘span’ 15-turn trim adjustments. The output process signal is indicated by the front LED, giving a clear indication of module function, presence of signal, and output loop continuity (current outputs only). The Conductivity Transmitter has input/output isolation avoiding grounding problems with interfacing equipment due to the conductivity of the fluid forming a connection to ground potential. RF and power transient protection is standard as it is with all BASI modules. Various power supply choices are available varying from 240Vac down to 8Vdc, all provide power isolation.