RU1794760C - Device for measuring conductivity of rail line isolation - Google Patents

Abstract

Use: for measuring the conductivity of a rail line insulation. Summary of the invention: the device comprises a signal generator 1. Current measuring units 5 and 6, a comparison unit 7 and a recorder 8. 1-5-7-8; 6-7.1 il.

Description

The invention relates to electrical measurements and can be, in particular, used in devices of railway automation and telemechanics, in particular in rail circuits.

A device is known for measuring and conducting the insulation of a rail line, comprising a current measuring unit, a signal generator connected through one of said terminals to one end of one rail thread of a rail line, and a recorder.

The problem to which the invention is directed is to increase the accuracy of measuring the conductivity of the insulation of a rail line.

The solution to this problem is achieved by the fact that the device for measuring the conductivity of the insulation of the rail line, comprising a current measuring unit, a signal generator, connected via one terminal through the indicated measuring unit to one end of one rail thread of the rail line, and the recorder is equipped with a comparison unit and an additional current measuring unit , one of the inputs connected to the other end of the first rail thread, the second input to one end of the other rail thread, the signal generator is connected to the other end of the rail, and the output measuring units connected to the input of a comparison unit, whose output is connected to the logger.

The drawing shows a structural diagram of a device that implements a method of measuring the conductivity of the insulation of the rail line ..

The device comprises: a signal generator 1, a rail line 2, one and the other rail threads 3 and 4, current measuring units 5 and 6, a comparison unit 7 and a recorder 8.

One output of the signal generator 1 is connected through a current measuring unit 5 to one end of one rail thread 3 of the rail line 2, the other end of which is connected through an additional current measuring unit G to one end of the other rail thread 4, the other end of which is connected to the other terminal generator 1, the outputs of both measurement units 5 and 6 are connected respectively to the first and second inputs of the comparison unit 7, the output of which is connected to the forming unit 8.

Measurement units 5 and G can be performed both on the form of reference resistors and on the form of Inductive and other current sensors; the comparison block b in its simplest form can be a differential transformer, the forming unit 8 can be made as in the form

a pointer device, calibrated in units of conductivity, and in the form of an analog-to-digital converter for the purpose of entering this information into a computer

for further work (not shown in the figure).

The device operates as follows.

With the diagonal action of the signal from the generator 1 through the measurement unit 5 on the rail line 2, on the opposite ends of the rail threads 3 and 4 and the signal from the free end of the rail thread 3 through the additional measurement unit 5 on

the free end of the other rail filament 4 in the device forms an electric circuit through which current flows and which in general will consist of two parallel branches: the first through the measuring unit 6:

secondly, a distributed branch along the entire line 2 - through the insulation conductivity available between the rail threads.

When a signal from the generator is supplied to the opposite ends of the conductors in the system, one rail thread - isolation - another

a rail current will flow, which is a function of the conductivity of the insulation,

Let us consider possible cases of changes in the permeability of the insulation.

Let the conductivity be zero. Then the current from the signal generator 1 will pass through the circuit: one output of the generator 1, block 5. rail thread 3, additional unit 6, rail thread 4 and the other output of the generator 1.

Blocks 5 and b measure the current flowing along these branches, and then the measured values are compared in block 7, and since the currents are equal at zero conductivity, the signal at the output of this block will be equal

zero, and therefore, in block 8, a value corresponding to a conductivity value of zero is generated.

When the conductivity is increased to the maximum, in addition to the above-mentioned electric circuit, a branch is formed, which includes the insulation conductivity, i.e. the leakage current is stronger, and this current will be the greater, the greater the conductivity, i.e. from the rail thread 3 more and more there will be a leakage current, and the current through block 6 is less and less. less. At maximum conductivity, it will be close to zero. Then block 6 measures the minimum possible current, and block 5 measures the maximum possible current.

After the comparison operation, in block 7, the maximum value will be output, and block 8 will form a value corresponding to it about the measured conductivity.

An analysis of the two boundary conditions allows us to conclude that the signal at the output of block 7 will be proportional to the conductivity of the insulation between the rail threads.

Claims (1)

SUMMARY OF THE INVENTION A device for measuring the conductivity of an insulation of a rail line, comprising a current measuring unit, a signal generator, connected through one of said terminals to one end of one rail of a rail line, and a recorder, characterized in that, for the purpose of increasing accuracy, it is provided a comparison unit and an additional current measuring unit, one of the inputs connected to the other end of the first rail thread, the other input to one end of the other rail thread, the signal generator is connected to the other end thereof, and the outputs of the measurement units are connected to the input of the comparison unit whose output is connected to the registrar.