How to Measure Capacitance?

May 02, 2016

Whether you are an engineer or a consumer, many daily applications involve capacitance. Capacitance can be measured using a capacitor, however it is not as simple as that. There are three different methods in which the capacitor measures capacitance. 

1.Displacement of Parallel Plates

  • Diaphragm deflections is simplest way to change 2.pngthe measure of capacitance, by varying the distance between electrode plates
  • This method measures the amount of energy that can be stored by the slight amount one electrode plate of the diaphragm deflects in response to changes in applied force
  • The diaphragm can deflect inwards or outwards (opening/closing gap)
  • Fun Fact: Setra uses this method by converting the change in capacitance into a linear analog output (voltage/current) for our pressure transducers


 2. Change in Area- Shift in Electrode Plates1.png

  • Measures capacitance between two moving electrode plates
  • As the plates move in separate directions, in respect to one another, the capacitance between the plates decreases

 3. Change in Dielectric Material

  • Dielectric material is an insulating layer 3-1.pngbetween the two conducting electrode plates
  • Dielectric material examples include solids and gases
  • Can be used with displacement parallel plates or change in area
  • Click here to view a dielectric constant chart


CLICK HERE to learn more about Setra’s Capacitance transducers. 

Topics: General Industrial, HVAC/R