Can I calibrate a Robertshaw Capacitance Level Instrument without knowing what level is in the tank?
Yes, it is possible, but the most accurate method is to calibrate to the actual process level. The alternative is to disconnect the probe and insert a capacitance signal into the instrument. This will require fixed capacitors or a pico-farad signal generator. The capacitance input must be calculated based on the dielectric of the process, geometry of the vessel, probe being used and mounting configuration. The Terminal Capacitance (see Question 5) must also be used for calculations. See example in the RF Level Controls Selection Guide.
