SU1566231A1 - Ultrasonic thermometer - Google Patents

Abstract

The invention relates to contact thermometry and can be used to measure temperature over a wide range. The purpose of the invention is to expand the measurement range and increase the measurement accuracy. The ultrasonic thermometer contains a resonator 1, connected via a matching link 2 and a communication line 3 with a converter 4. It also includes a generator 5, a modulator 6, a digital-to-analog converter 21, a frequency meter 22 and a recorder 24. In addition, the device contains amplifiers limiters 7 and 11 schemes 16 and 17, counters 12 and 13 and integrator 18. 2 Il.

Description

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The invention relates to the field of contact thermometry and can be used to measure temperature over a wide range.

The aim of the invention is to expand the measurement range while improving the measurement accuracy.

FIG. t shows a block diagram of an ultrasonic thermometer; 2 shows timing diagrams for his work.

The ultrasonic thermometer contains a resonator 1, a matching link 2, a communication line 3, a transducer 4, a generator 5, a modulator 65, a limiting amplifier 7 of the received signal, a starting signal 8 by a received signal, an imaging unit 3, an oscillator phase setting circuit 10, an amplifier - limiter 11 of the generator signal, counters 12 and 13, inverters 14 and 15, AND 16 and 17 circuits, integrator 18, frequency meter control circuit 19, NAL control circuit 20, CDL 21, frequency counter 22E, code converter 23, recorder 24, driver 25 strobe imgupsu and one-shot protection 26.

Moreover, the converter 4 input is connected to the modulator 6 output, the input of which is connected to the generator 5 output, the input of the meter 22 is connected to the latter, the converter 4 gateway is connected to the input of the amplifier 7 of the received signal, the input of the limit amplifier 11 of the generator signal is turned off to the generator output 5, and the output to the counting input of the interval imager 9, the output of the limiting amplifier 7 of the received signal is connected to the input of the circuit 8 in a -. . ; o, -v signaled - and the output is cx d-j -. : en, x. t yasm - to the input of the controls ™ l | 1l - generator 5, Vopsod sche- bsh. The 8 triggering signals are connected to the control input of the interval imager 9, the outputs of the two circuits 16 and 17 are connected to the direct and inverting inputs of the pulse integrator 18, the output of which is connected to the information input of the frequency control circuit 19 and the control input 20 of the control circuit 20 The DAC, the clock input of the DAC control circuit 20 is connected to the clock output of the modulator 6, the output of the frequency meter control circuit 19 is connected to the trigger input of the frequency meter 22, code outputs. 20 control schemes

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23

Q 5

Q d

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14

The DAC is connected to the code inputs of the D / A converter 21, and the output of the latter is connected to the frequency control input of the generator 5, the output of the frequency meter 22 is connected via the code converter 23 to the input of the recorder 24, the output of the interval mapper 9 is connected to the input of the phase setting circuit 10 the strobe pulse is connected to the output of the phase setting circuit 10, and the counting input of the strobe pulse generator 25 is connected to the output of the generator signal limiter 11, the output of the strobe pulse generator 25 is connected to the control inputs of the counter 12 and 13 and the resolution input of the frequency meter control circuit 19, the signal input of the first counter 12 is connected to the output of the limiting amplifier 11 of the generator signal, and the signal input of the second counter 13 to the output of the amplifier 7 of the received signal, the output of the first counter 12 is connected to one of the inputs of the second circuit And 17 and through the inverter 14 with one of the inputs of the first circuit And 16, and the output of the second counter 13 is connected to the second input of the first circuit And 16 and through the inverter 15 with the second input of the second circuit And 17.

Ultrasonic thermometer operates as follows.

From the clock output of the modulator 6, the pulses arrive at the clock input of the control circuit 20 of the 11AP, which leads to a change in the code on the code outputs and a change in the voltage on the output of the DAC 21. The voltage generated by the DAC goes to the generator 5, where it is converted to a frequency. The signal from the output of the generator 5 is fed to the modulator

The signal from the output of the modulator 6 in and / de sinusoidal radio pulse up t. is formed in the transducer 4 into acoustic oscillations, which, propagating along link 3 and matching link 2, are reflected from resonator 1, then through link 3 they flow to transducer 4, are converted into electrical oscillations (Fig. 2a) and are fed to input amplifier limiter 7 received signal. The signal in the interval (Fig. 2a) is the signal reflected from the resonator 1 when an excitation radio pulse falls on it, a. signal in the interval (i f3 Egt the resonant radiation signal of the excited resonator V.

For the time of transmission of the radio pulse, the protection single vibration 26 locks the pulse of the input of the amplifier-limiter 7 in order to avoid overloads and the electronic circuit from the signal of the modulator 6. The amplified and limited signal from the output of the amplifier-limiter 7 is fed to the trigger circuit 8 with its pulse (Fig 2c) starts the interval imager 9. The signal input of the latter receives a signal from the output of the amplifier-limiter signal generator (Fig.2g). The shaper 9 with its pulse (figd) sets the time interval from the front of the received signal before the start of operation of the oscillating system (resonator) in a steady mode of free damped oscillations (Fig. 2a). At the time of decay of a rectangular pulse (tf, Fig. 2e), the phase setting circuit 10, which is a single vibrator, by its pulse (Fig. 2e) disrupts the oscillations of generator 5 and imposes a new phase on it (t, in Fig. 2e). After the generator is phased, the pulse of the strobe pulse generator 25, which is generated by the pulse counting from the output of the amplifier 11, is fed (Fig. 2g) to the control inputs of counters 12 and 13. The last pulse countings from the output of the limiter amplifiers 11 and 7, respectively, form duration NT, (fig.2z) and MTG (.fig. 2i), where T, is the oscillation period of the generator, T. is the period of free oscillations of the resonator. FIG. 2 selected. These pulses are fed to the inputs of circuits AND 16 and 17, and the inputs to circuit 16 receive a signal from counter 13 (Fig. 2i) and a signal inverted by inverter 14 from counter 12 (Fig. 2k). A signal from counter 12 (Fig. 2h) and a signal inverted by an inverter 15 from counter 13 (Fig. 2n) are applied to the inputs of circuit 17. From the outputs of circuits 16 and 17, short pulses are removed, corresponding to the overlapping of the input signals (Fig. 2m, n). The duration of the pulses from the outputs of the circuits 16 and 17 is 10

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to the input of the resolution of the frequency meter control circuit 19, by its decline, its transfer to the initial mode.

The signals from the outputs of circuits AND 16 and 17, respectively, are fed to the direct and inverting inputs of the integrator 18 pulses. If the volt-second areas of the input pulses are different, then the output of the integrator 18 is the error signal, which is fed to the signal input of the DAC control circuit 20. Depending on the mismatch polarity, the code outputs of the control circuit decrease or increase the code, which leads to a change in the voltage at the output of the DAC 21 and a change in the frequency of the oscillator 5 until it recovers well. Then, the circuit 19 with its impulse transfers the frequency meter 22 to the frequency measurement mode. The automatic tuning of the oscillator signal frequency to the oscillation frequency of the resonator, which is the primary temperature measuring transducer, optimizes the excitation mode of the resonator due to the fact that 3Q frequency of the excitation signal is excited at the resonant frequency of the resonator at any temperature. This allows the measurement range to be expanded and the measurement accuracy to be improved.

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Claims (1)

Invention Formula An ultrasonic thermometer containing a resonator connected via a matching link and a communication line to a converter, the output of which is connected through a series-connected amplifier-limiter of the received signal and a triggering circuit by the received signal with the first input of the interval imager, the second input of which is connected to the output of the amplifier-limiter of the generator signal, the input of which is connected to the output of the generator and through serially connected frequency meter and code converter - with a recorder, the generator output is connected to the converter via a modulator, the second output of which is through one-channel between each other, if 55tor are connected to the second input those. the frequency of the equalizer signal generator 5 equalizer-limiter of the received signal to the frequency of free oscillations of the peson, the setup circuit of the phase of the generator 1, In addition, the impulse of the generator connected to the input of the generator, 25 strobe pulse rotor arrives first and second I circuits, outputs of which Compiler V.Yarych Editor N. Bobkova Tehred M. Didyk Corrector M. Sharoshi Order 1216 Circulation 495 VNIIPI State Committee for Inventions and Discoveries at the State Committee on Science and Technology of the USSR 113035, Moscow, Zh-35, Raushsk nab. 4/5 Subscription