SU1478129A1 - Instrument for measuring value of electric charge - Google Patents

Abstract

The invention relates to the field of measurement technology and can be used to estimate the amount of charge in an electrostatic discharge from electrified materials under production conditions. The aim of the invention is to reduce power consumption. The device contains a receiving electrode 1, a housing 2 with a scale 11, an axis 4 connected to an adjustable torque node 5, on which a rocker 6 is mounted of a conductive material, at the ends of which electret plates 7 are fixed. The opposite poles of the plates 7 are facing the metal plate 8 The discharge transfers the charge from the test surface to the electrode 1 and the housing 2. Then the switch 9 is set to a different position and the plate 8 is charged. Rotate arm rotates as a result of the interaction of the plates 7 with the charged plate Tina 8. 1 Il.

Description

The invention relates to measuring technique and can be used to estimate the amount of charge in an electrostatic discharge from an electrified material under arbitrary conditions.

The aim of the invention is to reduce power consumption.

The drawing shows the proposed device.

The device consists of a receiving electrode 1 and a recording unit containing a conductive housing 2, made, for example, of a transparent dielectric material with a leading coating 3. In the cavity of the housing 2, an axis 4 is connected, connected to an adjustable torque compensation unit 5. On the axis 4, a 2Q flat rocker 6 is made of a conductive material, to the ends of which electret plates 7 are attached, facing the conductive metal plate 8 with opposite poles 25. The plate 8 is electrically connected to the fixed contact of the on / off contact switch

9, the movable contact of which is connected to one of the capacitor plates

10, the second lining of which is connected to the leading coating 3 and the ground. A measuring scale 11 is applied on the inner surface of the housing 2. A switch 9 is mounted on the housing 2. 35

The device operates as follows.

During measurements, the switch 9 connects the electrode 1 to the capacitor plate 10. The electrode 1, located at the surface of the electrified material, causes significant distortion of the electrostatic field. When the breakdown voltage is reached, a spark pulse occurs — 45th discharge. According to the spark discharge streamer, electrostatic charges from a part of the surface of the electrified material flow to the electrode 1 and through the switch 9 to the capacitor 10. After the spark discharge passes, the device is removed from the electrified surface and the switch 9 is set to a different position. In this case, the electrostatic charges 55 from the capacitor 10 partially flow onto the plate 8. The distribution of charges, as in the case of their flow from the receiving electrode 1 to

2, the capacitor 10, and when flowing from the capacitor 10 to the metal plate 8 is determined by the ratio of the capacities of the respective nodes. Thus, a certain surface charge density is formed on the plate 8, which is proportional to the measured charge in a pulse from an electrified material. As a result of the action of electrostatic interaction forces, the plane rocker 6 mounted on the axis 4 rotates by a certain angle proportional to the surface charge density on the metal plate 8, the degree of polarization of the arms of the rocker arm 6, and the rigidity of the adjustable unit [5 of torque compensation.

The rotation angle is recorded on a scale of 11, deposited on the inner surface of the housing 2 of a transparent dielectric material. The polarization of the beam is due to the fact that the plane beam 6 is made of a leading material, and the electret plates 7 attached to the arms of the beam, face the opposite poles to its plane, as a result of which an induced charge arises on the arms of the beam 6, the sign of which corresponds to the sign of the charge of the pole of the electret plate 7. The presence of a conductive coating 3 connected to a common bus provides screening of the device, thereby eliminating the influence of external electrostatic fields on the readings of the device and by bilizing the capacity of the metal plate 8 relative to the ground.

The proposed device does not contain a power source, since in the process of its operation, the energy of the measured charge and the energy stored by the electret in the process of its manufacture are used. The lack of power sources and small overall dimensions allow the device to be used in a production environment, including in hazardous areas.

Claims (1)

Claim A device for measuring the magnitude of the electric charge, containing a receiving electrode and a drive housing connected to a common bus, characterized in that, in order to reduce power consumption, it is equipped with a conductive rocker placed in the cavity of the conductive housing on an axis with an adjustable torque compensation node conducting a plate, two electrode plates and a capacitor, while the housing is made with a switch and a scale located on the surface of the housing, the conductive plate is placed parallel but briefly, at the ends of which opposite poles of electret plates are fixed from the side of the conductive plate, the fixed contacts of the switch are connected respectively to the conductive plate and the receiving electrode, and the movable contact of the switch is connected to the first terminal of the capacitor, the second terminal of which is connected to a common bus.