RU2068180C1 - Device for nondestructive testing of strength of solid materials and articles - Google Patents

Abstract

FIELD: measurement technology. SUBSTANCE: device for nondestructive testing of strength of solid materials and articles includes multivibrator which one collector circuit incorporates standard capacitance and which other collector circuit includes working capacitive sensor. Secondary converter has power amplifier, null detector and register. EFFECT: simplified design, enhanced functional reliability. 1 dwg

Description

 The invention relates to instrumentation and can be used for non-destructive testing of the strength of solid materials and products.

 Known devices for non-destructive testing of materials and products (Arsh E. I. Auto-generating methods and measuring instruments. M. Mechanical Engineering, 1979, pp. 136-141, 150-157), when capacitive sensors are used with the sensor included in a single-circuit measuring oscillator. The disadvantage is the single-cycle mode of the oscillator when the inductive element is the main element of the resonant circuit.

 The closest in essence and technological capabilities is a capacitive concentration meter (Kryukov K.G. Farafontov A.I. A.S. N 1741044 G 01 N 27/22. B. I. N 22, 1992), containing a capacitive sensor , temperature sensor, generator and secondary converter. The generator is made according to the multivibrator scheme with one of the capacitance transistors and a working sensor included in the emitter circuit.

 Such a capacitive meter is designed to control the concentration of liquid media consisting of a mixture of components and is not suitable for monitoring the strength of solid materials and products. In addition, the inclusion of a capacitive working sensor in the emitter circuit of the transistor does not provide high sensitivity and a sufficiently sharp change in the frequency of the generator when monitoring conductive solid materials.

 The technical result of the invention is the expansion of technological capabilities and simplification of control, increasing its accuracy.

 The drawing shows a block diagram of a device for non-destructive testing of the strength of solid materials and products.

 The device comprises a capacitive working sensor 1, an alternating high-frequency voltage generator 2, a secondary converter 3, including a power amplifier 4 and a zero-organ 5 connected in series, connected to a recorder 6.

 Generator 2 is made according to the scheme of an asymmetric multivibrator, in one collector circuit of which a reference capacitance is included, and in the other collector circuit a working capacitive sensor is installed, mounted on a controlled sample or part.

 The use of an asymmetric multivibrator as an alternating high-frequency voltage generator with the inclusion of a reference capacitance and a working capacitive sensor in its collector circuits allows, in contrast to self-generated circuits and circuits with a capacitor and a working sensor to be included in the emitter circuit, to obtain high sensitivity and the required generator frequency difference in large range when using working capacitive sensors of various types and different capacities.

 The device operates as follows.

 When the device is turned on, an alternating high-frequency voltage appears at the output of the generator 2, the frequency of which depends on the ratio of the capacitance of the reference capacitor and the capacitance of the working sensor. In this case, the signal is amplified using a power amplifier 4, to which a null organ 5 and a recorder 6 are connected.

 In the absence of a controlled object at the generator output there is an electromagnetic signal of one frequency and a zero value on the scale of the recorder is set using the zero-organ. When a capacitive working sensor is installed on a controlled sample or part made of solid material, the sensor capacitance changes due to electromagnetic energy losses in the material of the sample or part, and a signal of a different frequency will be at the output of the generator. The change in frequency is recorded by the recorder and depends on the strength of the controlled object.

 The main advantage of an asymmetric multivibrator is its simplicity, versatility, reliability in operation, the ability to work with capacitive working sensors of various types and sizes when controlling samples of solid material and the products themselves. The inclusion of a reference capacitance and a capacitive working sensor precisely in the collector circuits of multivibrator transistors provides high control sensitivity, a sharp change in the frequency of the generator. In this case, it is possible to determine the strength of any solid materials and non-conductive electric products, such as concrete, marble, ceramics, bricks, concrete blocks, piles, beams and generally solid insulating materials.

 The range of controlled strength and sensitivity level are easily adjustable and set by changing the capacitance of only the reference capacitor in the collector circuit of a multivibrator.

 The device was tested with non-destructive testing of the strength of concrete cubes.

Claims (1)

 A device for non-destructive testing of the strength of solid materials and products containing a capacitive working sensor, an alternating high-frequency voltage generator and a secondary converter connected to the generator output, characterized in that the generator is made according to an asymmetric multivibrator scheme, in which one collector circuit includes a reference capacitance, and in another the collector circuit includes a working capacitive sensor designed for installation on a controlled sample or part, and the secondary converter contains IT series-connected power amplifier and the zero-body connected to the instrument, the registrar.