SU1469421A1 - Device for measuring physical characteristics of media - Google Patents

Description

(21) 4072033 / 24-25

(22) 03/24/86

(46) 03/30/89. Bul No. 12 (75) A.N.Hnpshn (53) 533.275 (088.8)

(56) USSR Copyright Certificate No. 1226246, cl. G 01 N 27/02, 1981.

Schwartz S. Semiconductor circuits. M., 1962, p. 153, 154.

. (54) DEVICE FOR MEASURING PHYSICS. CHARACTERISTICS ENVIRONMENT

(57) The invention relates to a measurement technique and can be used to measure electrical conductivity, dielectric constant.

magnetic permeability, residual magnetization media. The purpose of the invention-t nor - the expansion of the measurement range. The device contains a oscillator with an oscillating circuit transistor whose inductance or capacitance serves as a sensor. A transistor generator is included in the base of the transistor. A meter detector and an amplitude regulator detector are connected to the loop, and the widening of the measurement range is achieved by using the shock excitation mode of the circuit, which eliminates the limitations of the generator self-excitation conditions. 3 pe.

one ;.

The invention relates to a measurement technique and can be used to measure electrical conductivity, dielectric constant, magnetic permeability and residual magnetization of media.

The purpose of the invention is to expand the range of measurements.

FIG. 1 is a schematic diagram of an apparatus for measuring the physical characteristics of media; Fig. 2 shows a sensor, an exemplary embodiment; Fig. Z-Zpury voltages on the sensor circuit.

In the diagram (figure 1) indicated: 1, the sample under study; 2 - a sensor, which can be made in the form of an inductive (figure 1) or capacitive (figure 2) sensor with the addition of capacitance or inductance to the resonant terminal

O) C

tour; 3 and 4 - detectors; 5 - measuring device; 6 and 7 - capacitors;

8-generator transistor; 9 is a generator of rectangular pulses;

10 - capacitor. The emitter of the transistor is connected via a resistor 11 to the output of the regulating element 12, to the inverted input of which the source 13 of the reference voltage is connected, and to the direct voltage - voltage divider 14-15.

The device works in the following manner.

When applying to the base of the transistor 8 control pulses from the generator

9on is unlocked and shock oscillations are excited in the circuit of sensor 2, the odd half cycles of the oscillators flow through the detector 3 to the capacitor 7 and charge it to an amplitude value. The voltage from the capacitor through the resistive divider 14-15 is fed to the direct input of the operational amplifier. With changes in the electrical conductivity of the medium, a corresponding change in the voltage on the capacitor 7 occurs and the predetermined amplitude of the nespaoro half-period of free oscillations is restored; the amplitude of the second half-period does not stabilize and changes depending on the change in the conductivity of the medium. Detection of even half-periods is performed by detection 4, and registration by a voltmeter 5. The picture of the processes occurring in this is illustrated by the voltage plots on the contour of sensor 2 (Fig. 3). When the samples of metals with different conductivities are brought to the contour, the oscillation period changes slightly, and the amplitude of the second and subsequent oscillations decreases and the more noticeable the larger the specific resistance that the specimen brings to the contour at the contour frequency until the oscillation is complete.

For a quantitative assessment of the dependence of the voltage on the recording voltmeter 5 on the change in the electrical conductivity of the medium, coils of the contour of the sensor 2 are placed on a turn

to simulate the electrical properties of the medium.

The proposed device can be used to measure the dielectric constant of media. In this case, a capacitive sensor is used as a capacitor entering the circuit.

Claims (1)

Invention Formula A device for measuring the physical characteristics of a medium, comprising a generator on a transistor with an oscillating circuit of a sensor, a detector, a regulating element, a voltage divider, a reference voltage source, the oscillating circuit being included in the collector circuit, the regulating element being connected to the emitter of the transistor by one input through a voltage divider and detector - with an oscillatory circuit, and another input - with a source of reference voltage, characterized in that, in order to extend the range of measurements, it will complement flax contains a generator of rectangular pulses, a second detector, measuring instrument, wherein the generator of rectangular pulses is connected between the base of the transistor and the common bus, a detector is included IU Ed oscillation circuit and izmeritelim device. fieL FIG. 2 fW