JPS60123772A - Electrostatic potential measuring apparatus - Google Patents

Abstract

PURPOSE:To make it possible to perform accurate quantitative analysis even when potential distribution is not uniform and to enable the measurement of extremely low potential, by such a simple structure that a small gas discharge tube is interposed between a pair of electrodes chargeable by electrostatic induction. CONSTITUTION:When the charge amounts of electrodes E1, E2 exceed definite values corresponding to the shape and discharge gap length of discharge electrodes in a discharge tube GDT and the kind and pressure of sealed gas, the discharge tube GDT is discharged and voltage (the induction voltage of an antenna A) corresponding to the direction of the discharge current thereof is applied to a comparator circuit CO through an OR gate circuit OR and the circuit CO through a polarity reversal circuit PI and the circuit OR. When this voltage is higher than reference voltage applied to the circuit CO through a terminal TS, a FF circuit FF is reversed by the output of the circuit CO and a light emitting diode LED is allowed to emit light through a drive circuit DR to inform that the discharge tube GDT discharges. Therefore, if the discharge voltage with a definite value of the discharge tube GDT is foreknown, the potential of a place to be measured can be calculated.

Description

[Detailed description of the invention] The present invention relates to an electrostatic potential measuring device.

Conventionally, when measuring electrostatic potential, for example, an improved Persolium device or a rotating top electric field measuring device has been used, but the former has poor quantitative properties, and the latter has a complicated structure and has a poor potential distribution. Accurate measurement is possible when the potential distribution is uniform, but accurate measurement is impossible when the potential distribution is non-uniform.

An object of the present invention is to realize an electrostatic potential measuring device that has a simple structure, can quantitatively and accurately measure potential even when the potential distribution is uneven, and is capable of measuring 111 pairs of extremely low potentials. do.

The figure shows an embodiment of the present invention, where El is the electrode 5,
R2 is the ground electrode, GDT is a small gas discharge tube, one discharge electrode is connected to the electrode puller, and the other discharge electrode is connected to the ground electrode E.
It is connected to 2. SI is an insulating support that firmly supports the electrodes Kl, R2 and the discharge tube GDT using, for example, a suitable adhesive. A is an antenna, which consists of a small rod antenna or loop antenna with broadband characteristics.

RM is the antenna matching resistor, PI is the polarity inversion circuit, OR is the OR gate circuit, CO is the comparison circuit, T8 is the reference voltage application terminal, FF is the flip 70 amplifier circuit, R8 is the ZET switch, DR is the drive circuit, and LID is the It is a light emitting diode.

After resetting the flip-flop circuit FF, the electrode El
, E2 and the insulating support SI of the discharge tube GDT are positioned at arbitrary points in the DC electric field to be measured or the AC electric field to be measured, a charge corresponding to the potential to be measured is generated at the t pole EI due to electrostatic induction.
When the amount of charge exceeds a certain value, that is, a value depending on the shape of the discharge electrode in the discharge tube GDT, the length of the discharge gap, the type of gas filled in, the pressure, etc., the discharge tube GDT discharges, and the discharge current increases. A voltage corresponding to the direction of is induced in antenna A. The induced voltage of antenna A is OR gate circuit OR
It is applied to the comparison circuit co via Th, and is also applied to the comparison circuit Co via the polarity inversion port PI and the OR gate circuit OR.
is applied to the comparison port 1i through the terminal TS.
When the voltage is higher than the reference voltage applied to 8co, the output of the comparison circuit co inverts the flip-flop circuit FF.
The inverted output is applied to the drive circuit DR to cause the light emitting diode LED to emit light, thereby notifying that the discharge tube GDT has discharged. Therefore, if the discharge voltage of the discharge tube GOT, which is determined by the type and pressure of the filled gas, is known in advance, it is possible to know the discharge of the discharge tube GDT from the light emission of the light emitting diode I'IJD, and also to determine the discharge voltage at that time. ,
That is, it is possible to reduce the potential at the location to be measured.

Discharge tubes in which all or any of the parameters such as the shape of the discharge electrode, the length of the discharge gap, the type of filled gas, and the pressure are different, that is, the discharge tubes with different discharge voltages, are placed between the electrodes E1 and 82. Either prepare a large number of interposed tubes, or connect discharge tubes with different discharge voltages to a common electrode E1 and 8.
By configuring it so that it can be installed interchangeably between the two, any potential to be measured can be applied.

The figure shows an example where the electrode E2 is grounded, but it goes without saying that El may be grounded instead of the electrode E2.
Electrodes E1 and Ili! By keeping both electrodes floating without grounding them together, it may be possible to measure the potential difference.

Electrodes E1 and l1i2 are charged by induction and discharge tube GD
As long as it can discharge T, its material, shape, and method of supporting it to the insulating support SI may be arbitrary.Also, by forming the electrode in a small size within a range that does not cause corona discharge, high resolution can be achieved. Potential distribution can be adjusted.

The distance between the discharge tube GDT and the antenna A only affects the measurement sensitivity and is unrelated to the potential measurement value.
Since the reference voltage applied to O is applied for the purpose of preventing the light emitting diode LED from emitting light due to malfunction, the magnitude of the reference voltage may be appropriately selected depending on the expected potential to be measured.

Although the figure shows an example of a configuration in which the occurrence of a discharge is notified by light emission from the light emitting diode ED, it goes without saying that a buzzer or the like can be used instead of the light emitting diode, and the entire discharge detection circuit can be used. The configuration is not limited to that shown in the diagram,
The present invention can be implemented using any suitable circuit as long as it is capable of detecting discharge.

As is clear from the above description, the device of the present invention has a small gas discharge tube interposed between a pair of electrodes that can be charged by electrostatic induction, and the discharge that occurs when the induced charge on the electrodes exceeds one foot. It is configured to detect discharge in the tube and measure the electrostatic potential at the location where the electrode is placed.
By appropriately selecting the pressure, etc., it is possible to measure a much lower potential than when an air discharge is caused between charged electrodes in the atmosphere, and the potential to be measured is not limited to the space potential; A potential that can charge an electrode by an electric induction phenomenon, such as the potential of an object, is also possible, and in either case, it is determined whether it is a DC potential or an AC potential, or whether the potential distribution is uniform or non-uniform. In addition to being able to perform accurate quantitative measurements, the structure is simple and easy to handle, and has great practical effects.

[Brief explanation of drawings]

The figure shows an embodiment of the present invention, in which El and E2: electrodes, GDT: discharge tube, S: insulating support, A: antenna, RM: antenna matching resistor, P: polarity inversion circuit, O
R Nior gate circuit, CO: Comparison circuit, TS2 reference voltage application terminal, FF: Flip-flop circuit, Rs: R7.
DR: drive circuit, LED: light emitting diode.

Claims (1)

[Claims] (1) first and second electrodes that can be charged by induction;
A small gas discharge tube in which discharge electrodes are connected to the first and second electrodes, respectively, and a circuit for detecting discharge of this small gas discharge tube. An electrostatic potential measuring device characterized by: (The electrostatic potential measuring device according to claim 1, wherein either one of the first and second electrodes capable of being charged by induction is grounded.