SU1370448A1 - Electromagnetic thickness gauge - Google Patents

Abstract

The invention relates to non-destructive testing and can be used in various fields of national use to measure the thickness of dielectric coatings. The aim of the invention is to improve the reliability and accuracy of measurements due to the linearization of the output dependencies on the input parameters. The signal from oscillator 1 is fed to adder 5 both through converter 2, r-de, the dependence on the monitored parameter is entered into it, and also in the form of a reference signal generated by amplifier 8 and detector 9. After summation, the measured value is converted into a digital code and recorded with a digital indicator 7. At the same time, through the adder 10, the reference signal is fed to the reference input of the analog-digital converter 6, the process of normalization of the transformed information signal is carried out. 1 il. ate

Description

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The invention relates to instrumentation technology and can be used to measure the thickness of dielectric coatings.

The purpose of the invention is to improve the reliability and accuracy of measurements due to the linearization of the output dependencies on the input parameters.

The drawing shows a structural diagram of the electromagnetic thickness gauge.

Electromagnetic thickness gauge contains serially connected generator 1, converter 2, amplifier 3, detector 4, adder 5, analogue to digital converter 6 and indicator 7, connected in series amplifier 8, whose input is connected to the second output 1 of generator 1, detector 9 The output of which is also connected to the second input of the adder 5, and the adder 10, the second input of which is connected to the output of the adder 5, and the output to the input of the reference voltage of the analog-digital converter 6, as well as the quadrator 11, signal input which The key to the output of the adder 5, the reference voltage input - to the output of the detector 9, and an output - to the third input of the adder 10.

Electromagnetic thickness gauge works as follows.

The generator 1 feeds a sinusoidal current converter 2, the output signal of which is fed to the adder 5, amplified in amplifier 3 and detected in detector 4. The output signal of the same amplifying and detecting path including amplifier 8 and detector 9 is directly proportional to the generator generating current 1 and its operating frequency, is modularly summed in the adder 5 with a signal from the output of the detector 4. The output signal of the adder 5 is fed to the signal input of the analog-digital

converter 6. In addition, the output signal of adder 5 is summed algebraically in adder 10 with signals coming from the outputs of detector 9 and quadrant 11. At the same time, the output signal of the latter is directly proportional to the square of the output signal of the adder 5 and inversely proportional to the output signal of the detector 9. The output signal of the adder 10 is fed to the input of the reference voltage of the analog-digital converter 6 and is normalized for the signal fed to the signal input of the analog-digital converter 6. The output signal l Analog-digital converter 6 is supplied to a digital indicator 7.

Claims (1)

Invention Formula An electromagnetic thickness gauge containing a series-connected generator, converter, amplifier, and detector, and a series-connected analog-to-digital converter and an indicator that, in order to increase reliability and accuracy of measurements, it is equipped with an adder connected between the detector output and the analog input. a digital converter connected in series by a second amplifier connected to the generator, a second detector, the output of which is connected to the second input of the adder, and the second sum Hur, whose output is connected to a reference input of an analog-digital converter and a second input of the second adder connected to the output of the first adder, and the quad, the outputs of which are combined with the lane vtorm first and second inputs of the adder, and an output connected to a third input of the second adder.