Capacitance Level Transmitters
Level Transmitters
Level transmitters are electronic devices that send measurements of the liquid or bulksolid levels via an electromagnetic signal to a receiver. The receiver can be either a computer-controlled device or a user. This measurement information could be in the form of point level measurements (measurements taken at a specific level or at certain intervals) or as a continuous measurement (measurements within a specified range).
Transmitters usually consist of a power supply, an oscillator that emits the signal, a modulator to change the signal from one wave form to another, and an amplifier to increase the strength of the signal. Transmitters are contained within all electronic communication devices, as it is the unit used to send information. Transceivers are devices that contain both a transmitter and a receiver.
Level transmitters come in a range of different technologies for different applications, including hydrostatic, ultrasonic, capacitance, magnetic float, optical, conductivity and more.
NivoCAP
NivoCAP is a capacitance level transmitter distributed by Semrad Pty Ltd, designed to measure the level in vessels filled with conductive or non-conductive liquids, powders and granular materials. It is best suited for the measurement of conductive liquids in regularly shaped conductive containers, though with the use of an auxiliary probe it can also measure levels in irregular or non-conductive vessels. The probe must be continuously in contact with the medium for accurate measurement.
With capacitance level measuring, the probe is one ‘plate’ of the capacitor with the metallic wall of the vessel being the other ‘plate’. The dielectric of the capacitor consists of either the material itself if non-conductive, or by insulation on the probe if measuring a conductive medium. Level changes in the material may be correlated with changes in capacitance, which are then transformed in a 4 to 20mA analog signal by the electronics in the probe head.