SU729538A1 - Arrangement for measuring magnetic characteristics of materials and articles - Google Patents

Description

one

The invention relates to magnetic measurements, in particular, to devices for measuring the magnetic characteristics of materials and products.

A device for measuring the magnetic characteristics of materials and products is known, which contains two magnetic modulation sensors, a sample holder, a mechanism for rotating the sample, and a recording device 1.

However, this device does not have a sufficiently high measurement accuracy.

Closest to the proposed technical entity is a device / containing a differential magnetometer, a sample holder, a mechanism for rotating the sample, and a registering device 2,

However, this device has a low measurement accuracy, which is caused by errors resulting from induction magnetization and eddy current fields arising during sample rotation in a magnetic field.

The purpose of the invention is to improve the measurement accuracy.

This goal is achieved by the fact that a device for measuring the magnetic characteristics of materials and products, comprising a differential magnetometer, a mechanism for moving the sample holder and a recording device, is introduced. sequentially connected reference signal modeling unit and computing unit,

10, the second input of which is connected to the output of the differential magnetometer, the output to the recording device, and the input of the modeling unit of the reference signal is connected to the output of the mechanism for moving the sample holder, which is capable of reciprocating.

20 . The drawing is structural

scheme of the proposed device for measuring the magnetic characteristics of materials and products.

The device contains a differential magnetometer I, a sample holder 2, a sample 3, a mechanism 4 for reciprocating a sample, a unit 5 for simulating reference signals, a computational

30 block 6 and recording device 7.

Sample 3 or the product is fixed on the holder 2 so that during the movement of the sample holder by the mechanism 4, the reciprocating movement of the sample does not rotate or oscillate the sample 3 and the sample itself moves relative to the differential magnetometer 1.

The unit 5 for modeling the reference signals is made in the form of a potentiometric functional converter (or a set of functional converters), the movable contact of which is connected with the mechanism 4 for reciprocating the sample. The output of the differential magnetometer 1 is connected to the first input of the block b, the second input of which is connected to the output of the block 5 of the modeling of the reference signals. The output of the block b is connected to the registering device 7,

The device works as follows.

The test sample 2 is mounted on the sample holder 3 and using the mechanism 4 for reciprocating movement of the sample relative to the differential magnetometer 1, the output of which generates a signal F (t), which is the sum of the useful signal and random noise. This signal arrives at the first input of the computational unit 6. A moving contact of the potentiometric functional converter of the unit 5 for modeling the reference signal moves synchronously with the sample movement and the output signal Fg (t) arrives at the second input of the block b. so that the signal P (t) corresponds to the signal of the differential magnetometer from the reference sample.

At the output of block b, a signal is generated that characterizes the regression coefficient in accordance with the expression.

SoFA (t) F3 (t) dt ,,, - .jt F | (t) dt

This signal serves as a numerical charteristik of the magnetic state of the test sample.

If there are random ommehs at the input of the differential magnetometer 1, fluctuations occur at the output of the computing unit 6, the level of which decreases as the number of reciprocating movements of the sample increases.

The measurement time is selected depending on the level of fluctuations and the required accuracy.

In order to separately measure the various components of the residual and induced magnetization, measurements are made at different positions of the test sample relative to the magnetic field of the external field.

Use in the device of new blocks of the mechanism of reciprocating movement of the sample block

modeling of reference signals and a computing unit improves measurement accuracy by eliminating errors caused by eddy currents — changes in inductive magnetization during measurements

and random interference.

Claims (1)

1. USSR author's certificate No. 123606, cl. G 01 R 33/12, 1959. 2, US Patent No. 2665332, cl. 34-14-14, 1954, (prototype).