SU1446455A1 - Digital electromagnetic thickness meter - Google Patents

Abstract

The invention relates to electromagnetic thickness gauging and can be used to measure the thickness of large non-ferromagnetic materials and products. The purpose of the invention is to increase the measurement speed by assigning the operating frequency to the harmonic components of the mains voltage. The mains voltage pulses are fed to one of the inputs of the phase-sensitive detector 18, to the other input of which a signal comes from counter 20. The phase-sensitive detector 18 thus controls the frequency of the generator 19 of the controlled voltage. The triangular voltage produced by the digital-to-analog converter 22 becomes synchronous to the network frequency.

Description

This invention relates to electromagnetic thickness gauging of large non-ferromagnetic materials and products.

The aim of the invention is to increase the measurement speed by assigning the operating frequency to the harmonic components of the mains voltage.

The drawing shows a block diagram of a digital electromagnetic thickness gauge.

The thickness gauge contains a series-connected voltage converter 1 into a current and a field-creating coil 2, series-connected coils 3 and 4 of an induction converter, a key 5 connected between the common wire and the end of the coil 3 of the induction converter, and a key 6 connected between the common output of the coils 3 and 4 inductors and a common cable. In addition, the device contains ktachk 7 and 8, connectors, respectively, to both pins of the induction transducer coil 4 and the voltage converter 9 connected in series in a string of horizontal type, the input of which is connected to the keys 7 and 8, element 10 equivalence trigger 11, D-input which is connected to the common wire, the circuit 2I 12, the constructed decoder 13 and the block 14 of the indicator calculator. The device also contains an element 15, the output of which is connected to the indicator calculator 14, connected in series to terminal 6, network voltage generator 17, phase-sensitive detector 18, control voltage generator 19, the output of which is connected to the second input of circuit 2I 12 , a n-bit binary counter 20, an ambiguity block 21 and a digital-to-analog converter 22 whose output is connected to the control input of a voltage to current converter I, the second inputs of the equivalence block 21 and the equivalence element 10 chen to the n-th highlight of the n-bit binary counter 20,

the i-th output of which (i "logj {-)

where f is the frequency of the oscillator 19 of the controlled voltage) is connected to the second input of the phase-sensitive detector 18, and the outputs (n-2) -th and

Q

five

(p-1) -th p-bit of the south of the binary counter 20 is connected to the inputs of the gated-decoder 13 and element 2IL-15. In addition, the device contains a decoder 23 connected to the outputs (p-3) ( -2), (p-1) -m p-bit binary counter 20, element OR 24, connected between the third and fifth output of the decoder 23 and the control input of the key 8, element ZISH 25, connected between the fourth, sixth and eighth the outputs of the decoder 23 and the C-input of the trigger 11, the inverter 26, the output of which is connected to the control input of the key 6, and the input is combined with the control input of the key a 5 and connected to (p-2) -th output of n-bit binary counter 20, and connected in series the coil 27 and key 28, the output of which is connected to the input of the voltage converter 9 in the time interval, and the control input is connected to the trigger output 11, the Control input is not connected to the seventh output of the decoder 23.

The thickness gauge works as follows:

The logging coil 2 and the coils 3 and 4 of the induction transducer overlap coaxially on different surfaces of the object (not shown). A voltage is applied to terminal 16 from which the mains voltage driver 17 generates synchronization pulses of the phase-sensitive detector 18, the second input of which receives signals from the (p-4) -th output of the n-bit binary counter 20. The signal of the phase-sensitive detector 18 Thus, a controlled voltage generator 19, that its frequency becomes synchronous with the mains voltage harmonics. A successively connected equivalence unit 21, a digital-to-analog converter 22, and a voltage-to-current converter i create a triangular-shaped current in a woolen coil.

At the same time, the signals from the output of the n-bit binary counter are fed to the inverter 26, and through the decoder 23 and the OR element 24 to the control inputs of the keys 5, 6, 7, 8 and 28, switching them sequentially to register the voltage converter 9 into the interval time integrating type. Formed in this way the interval goes to

element 10 of equivalence, and then to the input of the installation of the trigger P. In the circuit 12, controlled by the trigger 1I, a strobe signal is generated | gated decoder 13. The output of gated decoder 13 is recorded by the block 14 calculation of dadikatsii, in which the signal from

voltage, p-bit binary counter, (p-4) -th output of which is connected to the second input of the phase-sensitive detector, equivalence blocks, the second inputs of which are combined and connected to the n-th output of the n-bit binary counter, digital-analog converter and

Claims (1)

the element OR 15, the value of Q is transformed by the voltage converter into the current, the measured value. The output of which is connected to the polishing line coil gated decoder and plug-in digital electromagnetic thickenes to (n-2) - and (n-1) -th outputs of measures, containing a polysozdanny coil. n-bit binary counter, junction, sequentially according to connected in series elements two coils of induction equivalence, connected to the nth razovatel, installed coaxially, | The output of a n-time binary counter is the first key connected between the average 2 o ka and the output of the voltage converter by the point of the coils of the induction transducer into the integrator spacing interval and the common wire, the second and the type, trigger, whose output is the third keys connected to the the second is connected to the control terminal of the input to the quad coil of the induction converter, that key, and the D input is connected to a voltage converter with a 25 wire and 2I circuit, the second time connected to the decoder, the second input of which is connected to a generator cerned and third yushochey, pho vshronatel controlled voltage and vysrd soe- mains voltage and connected po- d nen with gating input gating strobi- consequently | fuemy decoder desh11fratora Rui, inverter input and calculator block -shgdikatora ,. about t - the zo of which is combined with the controlling one that is in question, then, with the key of that key, and paged to (n-2) - how to increase & t the speed of measurement of the output of n-bit binary counting, it is equipped with a serial connection and the output is connected to the control unit coil over the polysadping coil and the fourth key, the output of which is connected to the voltage converter in an integrating type time interval, the fifth key connected between the free end of the first induction coil of the key and the ZILI element whose output of the converter and the common wire is connected to the C input of the trigger, the input is connected in series to the fourth, sixth phase-sensitive detector, the sub- and the eighth outputs of the decoder, and connected to the network network moy output coupled to the decoder voltage, generator controlled by g control input of the second key. 35 the input of the first key, the decoder connected to (p-3) -, (p-2) - and (li- -1) th outputs of the n-bit binary counter, an OR element connected between the third and fifth outputs of the decoder and the control input of the third