How is the value of vessel capacitance measured?
There are various methods by which the value of the capacitor can be measured. The suitability of the method depends on a number of factors such as; range of capacitance values to be measured, end purpose of measurement, (that is limit switching or continuous indication), type of output required (digital or analog) etc. Normally for level measurement capacitance values range from 30 to 1200 Pf for switching applications whereas 30 to 5000 Pf for continuous measurement. Following methods are popular: – • Probe capacitance forms one arm of a bridge circuit having a radio frequency (RF) source. Frequencies used are between 100 KHz and 1Mhz. • Probe capacitance forms an element of the frequency determining circuit in an Oscillator. • Probe capacitance forms a feedback-controlling element in a critically tuned Oscillator. • Probe capacitance forms the charging element in a constant current charging Circuit. • Probe capacitance forms an element that shifts the phase in relation with a Refere
