Technical Reference; Operating Principles - Siemens Pointek CLS200 Operating Instructions Manual

Technical reference

A.1

Operating principles

In capacitance measurement
wall) acts as the reference electrode of a variable capacitor, and the probe supplies the
measurement electrode. The dielectric
solid, or a combination) and, if the measurement electrode is insulated, the insulating layer.
①
②
③
④
⑤
⑥
The capacitance when the probe is uncovered (capacitance in air) will be different from the
capacitance when the probe is covered (for example, capacitance in water). If the product is
two immiscible liquids with different relative dielectric constants, (for example, oil and water)
the capacitance will change at the interface between the two liquids.
For definitions relating to capacitance, see the Glossary.
1)
The relative dielectric constant of air (vacuum) is 1: all other materials have a higher value.
2)
Pointek CLS200/CLS300 digital
Operating Instructions, 05/2021, A5E47904060-AA
Internal vessel wall
Dielectric = contents plus insulation (non-conductive contents)
Dielectric = insulation (conductive contents)
Probe diameter (d)
Insulation (probe sleeve)
Internal vessel diameter (D)
inside a vessel or silo, the environment (typically, the vessel
1)
is composed of the vessel contents (air, vapor, liquid,
2)
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