SU855572A1 - Ferro-probe coercion meter - Google Patents

Description

The invention relates to magnetic measurements and can be used for non-destructive quality control of ferromagnetic products. Devices are known for non-destructive testing of the structure and mechanical properties of ferromagnetic products by the coercive force measured after magnetization of these products with the solenoid 1}. These devices do not allow measurements on products whose dimensions are larger than the diameter of the solenoid, as well as quality control of the surface layers on the products. Closest to the one proposed is an electrocytermeter containing an attached electromagnet with a built-in electromagnet. bath in it by a flux-gate sensor (ferro-sensor) G21. However, the readings obtained for the same product are different for different coercimeters. This complicates their standardization, interchangeability and leads to the need to establish correlation of the test properties of products with indications individually for each device. The purpose of the invention is to increase the reliability of measurements of the mechanical properties of ferromagnetic products. This goal is achieved by the fact that a fluxgate coercimeter containing a source of magnetizing current associated with the winding of magnetization of an attachment electromagnet, the demagnetization winding of which is connected to a current source and a device for its registration, a sequentially connected source of current excitation, a flux probe, a phase detector, and a detector and a detector. current measurement, equipped with a voltage shaping and regulation unit, the input of which is connected to the output of the demagnetizing source t Single Exit - a current measuring device, and the electromagnet winding of attached demagnetization resistor shunted. FIG. 1 shows a block diagram of the device; in fig. 2 - a graph of dependence of the testimony of a countermeter (Sr) on the coercive force (HC) of products of specified sizes. The device circuit contains a source of magnetizing current 1, a source of excitation current of a fluxgate sensor, a test product 3. winding 4 electromagnet and demagnetizing electromagnet, ferroelectric sensor .5, resistor b, shunting demagnetization winding, phase out sensitive detector 7, millimeter / meter, meter, meter, meter, and a meter. with microammeter 10, unit 11 for shaping and adjusting voltage, measuring 1 times synchronously with a change in demagnetizing t, eye.

The device works as follows.

Previously, oftomki 4 include a source of magnetized current of one thousand. After the magnetization cycle, the exciter current source of the ferro sensor is turned on, while the needle of the microammeter 10 deflects to the left against the stop. Then, the source 9 of the demagnetizing current is switched on the windings 4, this current is gradually increased until the arrow of the microammeter 10 takes up the zero position. The coercimeter is indicated by the current Zp, recorded by a milliammeter 8 with a zero reading of the microammeter 10.

Mathematically, the connection of Sp and H is possible: T1 is the expression

where OQ is the demagnetizing current of an electromagnet (part of the coercimeter readings, due to the presence of the coercive force of the electromagnet core)}

K - regression coefficient. From the expression (1) it can be seen that the adjustment of the coercimeters in order to obtain identical readings Зр (combination of lines 12 and 13 in Fig. 2, where line 13 is a plot of Зр (Н) for another coercimeter) can be made by simultaneously changing the parameters. H and K .

If, for a sample with a coercive force H, the difference in the readings of two coercimeters is у р «Or З Ор I, then the current equal to L h can be diverted from the demagnetization winding 4 (Fig. 1) to a resistor 6 of a certain size. However, the coercimeter readings for the sample with the coercive force P differ (when shunting line 12 takes position 14). To make it possible to combine lines 12 and 13, it is necessary to make a change in the angle of inclination of the line Зр (Hg). This can be achieved by including a positive or negative voltage across the microammeter 10 (Fig. 1) to obtain a zero reading of this device with a larger or smaller Zr. FcU increment of this voltage, which determines the angle of the Zr line (Hj.), can be adjusted using block 11. The voltage polarity U is selected by block 11 in

5, depending on whether it is necessary to increase or decrease the angle of inclination of the line Зр (н.).

The release of coercimeters with identical indications on products that improve their metrology, reduces the costs of consumer plants associated with the calibration of each instrument, facilitates the operation of instruments.

Claims (2)

Invention Formula A fluxgate coercimeter containing a source of magnetizing current associated with a magnetizing winding. 0 an attachment electromagnet, the demagnetization winding of which is connected to a current source and a device for registering it, serially connected source of excitation current, fer5 probe, phase sensitive sensor and current measuring device connected to it, in order to improve the reliability of measuring mechanical properties ferromagnetic products, it is equipped with a voltage shaping and control unit, the input of which is connected to the output of the demagnetizing current source, the output to the measuring device and the demagnetization winding of the attached electromagnet is shunted by a resistor. Sources of information taken into account in the examination 1. Instrument making and automation means of control. Collection. M., VINITI, 1961, 169-221. 2. Defectoscopy. 1978, 1, 14-22.