SU830254A1 - Electric capacitive meter of non-electric values - Google Patents

Description

(54) ELECTRO-CAPACITY METER OF NON-ELECTRIC VALUES

additional electrodes located along the edges of the guard, and two additional windings having inductive coupling with the measuring and connected to the guard and additional electrodes.

In addition, to improve accuracy, the additional and measuring windings of the measuring bridge can be made of coaxial cable, the central core of the cable being the measuring winding and the screened cable braid the additional winding.

The drawing shows the device. The electro-capacitance meter contains a measuring bridge with inductively coupled arms. The system of electrodes consists of measuring 1, guard 2 and additional 3 electrodes. Additional electrodes 3 are located along the edges of the guard. The measuring windings 4 are inductively coupled to additional windings 5, which are connected to guard and additional electrodes. The device also contains a compensation capacitor 6, a current meter 7 and an alternator 8.

In the initial state, the current flowing through the capacitance between the guard 2 and additional 3 electrodes does not affect the equilibrium of the bridge, since the capacitance between these electrodes is the load only for generator 8, which can be chosen sufficiently powerful. The capacitance between the measuring 1 and guard 2 electrodes also does not affect the equilibrium of the bridge, since these electrodes are under equal potentials, therefore, there is no current through these capacitances. The operating current flowing through the capacitance between the measuring 3 electrodes is compensated by the current through the compensation capacitor 6, i.e. the bridge is balanced. When an electrically conductive particle appears between the electrodes of the device, the capacitance between the guard 2 and additional 3 electrodes changes, changing the latter leads to a change in the equilibrium of the bridge, which is fixed by means of a current meter 7, Moreover, the appearance of electrically conductive particles in the field of electrical symmetry ( In the drawing, this area is located between electrodes 2 and 3) leads to a significant shielding of the electric field of the measuring electrode 1, since the particle being monitored will be at zero potential. Consequently, the current of the measuring device also varies significantly. To ensure equality of potentials on the measuring and guard electrodes, it is necessary to provide close inductive coupling.

between the measuring and additional windings, which can be achieved by making these windings from a coaxial cable, the central core forming the measuring winding and the screened braid an additional winding. The appearance of an electrically conductive film on the electrodes with an increase in the humidity of the environment leads only to an additional load on the generator. The current through the film between the measuring / and guard electrodes does not flow, since these capacitances are under equal potentials.

The device works as follows.

First, the measuring bridge is balanced by the measuring current 7 using the compensation capacitor 6, then

0 between the transducer electrodes controlled environment. In the absence of electrically conductive particles, the measuring bridge is balanced even when the ambient humidity changes. The appearance of an electrically conductive particle 5 Ci leads to the imbalance of the bridge and the appearance of an output signal with positive and negative extrema, which is typical of particles in a dielectric flow.

0 A uniform change in the dielectric constant of the controlled medium can only lead to a change in the component of the output signal.

The proposed device allows

5 to control the electrically conductive particles in the gas stream with high accuracy and sensitivity, and can also be used to improve the control of the diameter of the microwire

0, etc.

Claims (2)

1. Authors certificate of USSR 9 356451, cl. G 01 B 7/00, 1962. 2. US patent 2950436, cl. 33-127, 65 1970 (prototype). 77/7 / 2 W E 7777 7777. “F ////, Zzm R