3383 25 kV Standard Gas Capacitor0 pages

3388
Compressed Gas Standard Capacitor

The compressed gas standard capacitor is an
indispensable instrument in every high voltage
laboratory and test field where it occupies a wide range
of important functions.
The compressed gas capacitor is used as capacitance
standard in bridge circuits to measure the dielectric
dissipation factor tan , the dielectric constant r
respectively the capacitance of cables, ducts,
insulators, transformer windings and insulates.

DESIGN FEATURES
The capacitor consists of the following main elements:
-

high-polished cylindrical electrodes
casing serving as pressure vessel, high voltage
connection, duct for test electrode and shield,
gas inlet valve
mental base with shielded plug and ground screw

The compressed gas capacitor is filled
with sulphur hexafluoride SF6 and
under pressure

ADVANTAGES
Excellent capacitance constancy Changes in
atmospheric pressure and humidity without
influence on capacitance
Small dielectric dissipation factor tan
Partial discharge free
Possibility to neutralize partial capacitances
influencing measurements with voltage regulator

0 Guard electrode
1 High Voltage electrode
2 Test electrode

APPLICATIONS
In combination with a C tan measuring bridge the
standard capacitor is used to measure loss factor and
capacitance of a high-voltage test object. By using type
2801 the interfering stray capacitances can be eliminated
completely by adjusting the screen system to the input
potential of the bridge.

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