Voltage measurer for eliminating variation and thermoelectric potential influence

Abstract

A voltage measuring instrument capable eliminating variation and thermal potential effect includes a first stepping panel composed of a measuring panel and two bracket panels without containing resistance, a second stepping panel comprising a measuring panel formed of a ring connected by ten resistance of 100 ohm and a 10 ohm resistances, a bracket panel formed by a 10x5 ohm, a third stepping panel comprising of a measuring panel of 10x10 ohm and a substitution panel. Each contact of the forth stepping panel is connected with the corresponding contact of the measuring panel of the third stepping panel, and the measuring panels are connected by conductors without on-off switch, which is capable of ignoring variation and thermal potential effect when performing measurement by voltage measuring instrument. The voltage measuring instrument is provided with four extended ranges of x10, x1, x0.1 and x0.01 with the maximum measuring voltage of 2.31V, the minimum resolution of 0.1muV.

Description

technical field [0001] The invention relates to an instrument for measuring DC voltage. Background technique [0002] At present, for a potentiometer with four measuring discs, the connection between the four measuring discs is generally switched by a switch in the middle disc, which will cause a change in contact resistance and limit the resolution. In order to overcome this problem, large electric brushes are generally used to increase the contact area, and silver-copper composite materials are used; application number 200510062369.6 discloses a new method for solving the deterioration of switch contact resistance by a potentiometer with four measuring discs. The first and second stepping discs are composed of a measuring disc and a replacement disc. The resistance values ​​on the measuring disc and the substituting disc are the same. Every time a resistance is added to the measuring disc, the substituting disc will reduce the same resistance. 3. The fourth stepping disc ...

AI Technical Summary

Problems solved by technology

The four measuring discs are connected between the two measuring terminals, so that the brush on the stepping disc switch is excluded from the measuring circuit, and there is no switching between the resistances on the four measuring discs, so there is no variation; Since the potentiometer step disc switch rotates at an angle of 15° for each step, 24 contacts can be distributed on each layer. There are resistances on each layer, and the inner layer’s resistance is out of tolerance, which will cause inconvenience to maintenance. The fourth stepping plate has half layers of measuring plate, replacement plate and auxiliary plate. The stepping plate switch also needs two layers inside and outside, and the inner layer also has resistance. Maintenance is also inconvenient

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