SU408243A1 - METHOD OF MEASUREMENT OF PARAMETERS OF ELECTRIC OR MAGNETIC FIELDS - Google Patents

Description

one

The invention relates to a measurement technique and can be used to measure the intensity of the electric n-ducts of magnetic fields at a given point in space.

The known method consists in that a ferroelectric or ferromagnetic core is placed in the field under study, excites the core in an auxiliary electric magnetic field, and according to the Change in the permeability of the core, the measured parameter is measured.

However, the known method has insufficient measurement accuracy due to hysteresis in the core, which leads to displacement and fluctuation of the device and the presence of Barkhausen jumps, which during cyclic polarisation or remagnetization of the core form the COMPOSITE and discrete noise spectra that limit the threshold of sensitivity. .

The aim of the invention is to increase the accuracy of measurement of the parameters of an electric or magnetic field.

For this, the cores are heated to the Curie point, the temperature is periodically changed near this point, an electrical signal is extracted with a frequency of temperature changes, according to which the measured parameters are judged.

The method provides high accuracy of measurements due to the fact that the core is periodically transferred to a state when its residual polarization or magnetization is destroyed. In addition, the effect on permeability is carried out without polarization reversal or remagnetization of the cores along limit hysteresis loops, which excludes the presence of a flat spectrum of noise due to Barkgausen jumps.

The drawing shows a functional diagram of the measuring device that implements the method.

The device consists of a primary converter 1, containing a ferroelectric or non-ferromagnetic core and connected to HEM, respectively, of an insert or coil, of a heating device 2,

combined with or located in the immediate vicinity of the converter, inertial temperature controller 3, low-energy thermal injector 4 having thermal contact with the core

a converter, a generator 5, a power supply injector, a selective amplifier 6 tuned to the frequency of measuring the permeability of the core, a synchronous detector 7 powered by a generator, and a recording device 8.

The device operates as follows. The converter is placed in an external measured field. The core is heated to the temperature of the Curie point. With the help of the inertia-O .NH of the regulator stabilize the temperature atur near this point. Then, using an injector, periodically with a frequency of several hundred or thousand hertz, they change the temperature of the core, as a result of which the latter periodically loses and acquires the properties of ferromagnet & electrician or ferromagnet. In this case, the induction (D or B), due to an external constant field (E or B), periodically changes and a signal appears in the output circuit proportional to the external field, which is amplified, demodulated, and recorded. The sensitivity threshold of such devices can be reduced by 1-2 orders of magnitude compared to those known for the same purpose.

 Subject invention

A method of measuring the parameters of an electric or magnetic field, based on a change in the permeability of ferroelectric or ferromagnetic cores, characterized in that, in order to increase the measurement accuracy, the cores are heated to the Curie point, the temperature signal | temperature changes, according to which measured parameters are judged.