SU1241072A1 - Ultrasonic thermometer - Google Patents

Abstract

The invention relates to the field of temperature measurements and to find a use in creating test equipment. The purpose of the invention is to improve the measurement accuracy. The device contains a pulse generator 1, a piezo emitter 2, a piezer receiver 3, a filter 4, time selectors 5 and THEN, a threshold device 6, a trigger 7, a functional converter 8, a digital tape recorder 9, a peak detector 11 and an amplifier 12. Introduction of new elements and the formation of new The connection between the elements of the device allows the temperature of the piezo emitter 2 and the piezo receiver 3 to be kept constant, which eliminates the parasitic modulation of the signal and increases the stability of the device 4 2 il / i (L

Description

The invention relates to temperature measurements, namely to ultrasonic thermometers, and can be used to create test equipment.

The aim of the invention is to increase the measurement accuracy by reducing the measurement error caused by the temperature change of the piezo emitter and piezo receiver.

Figure 1 shows the block diagram of an ultrasonic thermometer; on; FIG. 2 shows temporary diagrams illustrating his work.

The ultrasonic thermometer contains a pulse generator 1, a piezo emitter 2, a piezo receiver 3, a filter 4, a first time selector 5, a threshold device 6, a time interval former — for example, three gangster 7, a functional transducer 8, a digital tape recorder 9, a second time selector 10, peak detector If, amplifier 12, cooling system of piezo transducers 13 and synchronization unit 14.

Ultrasonic thermometer operates as follows.

When you turn on the device at time t (figure 2) block 14 synchronization, PA40

In autogeneration mode, the driver generates another pulse (figd), which starts pulse generator 1, sets the first 5 and second 10 timers to the initial state and also, in the unit state, the time interval former 7 (figure 2). A piezo emitter 2, excited by a pulse arriving from the output of a pulse generator, emits an ultrasonic signal, which travels a distance J in a controlled environment and after a time enters the piezo receiver 3 (FIG. 25). Signal with piezo; the receiver enters through the filter 4 to 45 the first time selector 5 (Fig. 2 S) V ac of its output - to the input of the threshold device 7 with a predetermined response threshold. At the exit of which I have worked out-. It has a pulse when the value of the 50 input signal exceeds its threshold. This impulse arrives at the input of the time-interval imager and puts it into the zero state (Fig. 2)., 15

The time interval T formed is uniquely related to the measured temperature, as the travel time

The ultrasonic signal of the distance i between the piezo emitter and the receiver is uniquely associated with the temperature of the controlled medium. The formed time interval by the functional converter 8 is converted to the value of temperature 6 and this value is recorded in digital form in a digital tape recorder.

 In principle, the operation of the circuit for controlling the flow rate of the cooling liquid is based on the constant monitoring of the amplitude of the reflected ultrasonic signal from the waveguide.

t5 piezoelectric transducer 2 and adjusting the decoction with the help of system 13 for cooling the transducers with this value, since the magnitude of the amplitude depends on. heating the waveguide piezo.

20 For analyzing the amplitude of the time selector 10, it passes only a five-fold reflected signal .. This is necessary for the time decoupling of the reflected signal and electric wiring from the pulse that drives the piezo-radiator. The reflected signal pro-. walking time selector 10 and detected by the peak detector 11 is fed to amplifier 12, and its

30 outputs to the control input of the converter cooling system. The converter cooling system 13 includes a reference voltage source, the voltage of which of the selectors 35 corresponds to a certain temperature of the waveguide. The magnitude of the signal postulated from the output of amplifier 12 is compared with the magnitude of the reference voltage and the resulting difference signal is used to control the execution mechanisms of the coolant flow control. Since during the operation of the automatic flow control circuit, the temperature of the waveguides is piezo. Since the emitter and piezo receiver are kept constant, this also eliminates the parasitic modulation of the signal due to a change in the temperature of the waveguides of the piezo receiver and the piezo receiver, which leads to thermometer operation stability.

All elements of the device can be implemented on standard microcircuits.

Claims (1)

Invention Formula An ultrasonic thermometer containing a pulse generator is connected to the Invention Formula An ultrasonic thermometer comprising a pulse generator is connected to a piezo emitter, acoustically coupled to a piezo receiver ,. the output of which is connected to the series: connected filter, the first temporary selector, the threshold device, the shaper of the time interval to the functional generator. and a digital tape recorder, a synchronization unit, the control outputs of which are connected to the control inputs of the pulse generator, the first time selector and the time interval generator., the cooling system associated with the piezo emitter and the piezo receiver 1-0 Edited M. Kelemesh Compiled by V.Kulikov Tehred M. Khodanich Proofreader J. Pojo. Order 3479/36 Circulation 778 Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Production and printing company, Uzhgorod, st. Project, 4 No one, characterized in that, in order to improve the measurement accuracy by reducing the measurement error caused by the temperature change of the piezoelectric transducer and the piezoelectric receiver, a second time selector, a peak detector and an amplifier, the output of which is connected to the control input of the cooling system, are inserted in it, the input of the second-time selector is connected to the output of the pulse generator, and the control input is connected to the output of the synchronization unit. - t .Kx- and