Elastic contact three-electrode device

Abstract

The invention discloses an elastic contact three-electrode device, and relates to equipment for measuring the dielectric constant and loss angle tangent of an electric insulation material. The device comprises a high-pressure electrode (1) connected with a high-pressure end H of a balanced bridge, and a test sample (2) on the high-pressure electrode (1), wherein a measuring electrode (13) and a shielding electrode (3) connected with a protection end G of the balanced bridge are arranged on the test sample (2). The device is characterized in that: the top of the measuring electrode (13) is provided with a metal corrugated pipe (12), a corrugated pipe suite (11), an insulation support (10) and a measuring end connector socket (9) connected with a measuring end M of the balanced bridge; the shielding electrode (3) is connected with an upper shielding electrode (6), an upper shielding electrode cover plate (7) and a counter weight (8) through a shielding electrode connecting ring (4) in threaded connection with the shielding electrode (3); and a measuring electrode positioning ring (5) is arranged between the measuring electrode (13) and the shielding electrode (3). The device has high measuring accuracy and is suitable for a thick film or a thin flat plate with a low-loss medium.

Description

technical field [0001] An elastic contact-type three-electrode device relates to a contact-type three-electrode device in a balanced electric bridge for measuring the dielectric constant and loss tangent of electrical insulating materials. Background technique [0002] Using a balanced bridge to measure the permittivity and loss tangent of the insulating medium under power frequency has high measurement sensitivity and high measurement accuracy, so it is widely used in the electrical insulation industry. The corresponding Chinese national standard (GB1409-88) and IEC standard (IEC 250-1969) and American ASTM standard (ASTM D 150-98 (2004)) suggest that the measuring electrodes all adopt a three-electrode system. However, so far, the simple three-electrode system is composed of a cylindrical measuring pole and a circular guard pole. Since the measuring pole of the above-mentioned three-electrode system is not shielded, it is susceptible to external electromagnetic interferen...

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Problems solved by technology

In order to prevent this situation, the method of increasing pressure is adopted, and the measuring electrode is in close contact with the sample, but it may cause unnecessary deformation of the sample, and the overall structure of the measuring device is very complicated.

[0004] The supporting accessory Agilent 16451B dielectric test fixture produced by Agilent Company of the United States also has a set of three-electrode devices. The measuring pole and the protective pole are fixed, the gap is very small, about 0.2mm, and they are not on the same plane, and the protective pole is slightly smaller. Indentation, which avoids the problem of small air gaps in the measurement area when the sample to be tested is not ideally flat, but the dielectric loss of the empty electrode of this electrode is relatively large, and it cannot be used for accurate measurement of the medium materials with little loss

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