SU917003A1 - Device for measuring temperature difference - Google Patents

Description

I

The invention relates to heat engineering measurements and is intended for the measurement of temperature differences on the seabeds of the seas and oceans, as well as can be used in various fields of industry and in scientific research.

A device for measuring the temperature difference is known, which contains temperature-sensitive piezoresonators, which convert temperature values in two points to the pulse frequency, which are used to determine visually the temperature difference between daum points P.

The drawback of the device is the low measurement accuracy due to the large error in the visual determination of the difference in thermal shading.

The closest to the proposed technical essence and the achieved result is a device for measuring the temperature difference, containing a frequency divider, a pulse counter, two located in different measuring tops and one time specifying auto-generators with piezo-resonators 2.

The disadvantage of the device is low measurement accuracy due to the presence of a thermostat for the driving cavity, which distorts the temperature distribution at the measurement points during autonomous operation of the device.

The purpose of the invention is to improve the accuracy of temperature measurement.

The goal is achieved by inserting a second pulse counter into the device,

10 two keys and a computing unit, and the time master oscillator connected to the input of the frequency divider is located together with one of the measuring oscillators, each of the KOTOpbix through the key and the pulse counter

15 is connected to the corresponding input of the evaluation unit, and the output of the frequency divider is connected to the control of the input keys.

The drawing shows a block diagram of a device for measuring temperature differences.

M

The device contains measurement autogenerators 3 and 4 placed in test media 1 and 2, respectively, autogenerator 5 sets the time, all autogenerators are equipped with 39 temperature-sensitive piezoresonators, and the autogenerator 5 is connected to the frequency divider 6, the outputs of which are connected to the control inputs of electronic switches 7 and 8, through which the measuring oscillators are connected with the inputs of pulse counters 9. and 10, the outputs of which are connected to the computing unit 11. The device works as follows. The autogenerators 3 and 5 with thermo-sensitive resonators placed on Wednesday 1 convert the temperature tj into frequencies — hence neither pulses fi and fj, respectively fi foi - “kit, fa fo2 + kjtz where fj, f are the pulse frequency of self-oscillators 3 and 5 ; f, f p, j are the nominal frequencies of autogenerators 3 and 5, respectively; k, k, are the thermal sensitivity coefficients of the autogenerators 3 and 5, respectively. An auto-oscillator 4 with a temperature-sensitive piezoresonator placed on Wednesday 2 converts feMnepaTj-py tj into the pulse frequency f. 3 fo3 + ksta, where f is the pulse frequency of the auto. . generator 4;

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Claims (2)

At-Cifti) High sensitivity and accuracy, cost effectiveness due to low electrical power consumption due to the absence of thermostating, high stability of the characteristics of piezoresonators in time and their linearity allow using the proposed -. my invention for measuring temperature differences in various industrial fields and in on-line studies, especially when measuring small values of temperature differences. The invention The device for measuring the temperature difference, containing a frequency divider, a pulse counter, two measuring stations located at different points and one time specifying oscillators with piezoresonators, TL and K lNiKa-Noti) fj, - nominal frequency of the oscillator 4; kt, is the thermosensitivity coefficient of the autogenerator 4. Using the autogenerator 5 and the frequency divider b with the division factor NQ, a measurement time interval is formed with a duration T equal to Y - - - "" - fa At time C, two electronic keys 8 and 7 simultaneously open the passage of pulses from the oscillator 3 to the counter 9 pulses and from the oscillator 4 to the pulse counter 10. During the time Tg the electronic counter 9 pulses will be counted N pulses (fo. + loa + Ka-t / a by the counter 10 will be counted N i pulses .e -By H3MepeHHbi; vl The values of the temperatures tj and tj) are determined on the starting points N ,, and N in the computing unit 11, followed by determining the temperature difference (ti-tj) in the following way: with the aim of increasing the measurement accuracy, A second pulse counter, two keys and a computing unit are entered, and the time set oscillator connected to the input of the frequency divider is located together with one of the measurement oscillators, each of which is connected to the corresponding input of the computing unit through the key and pulse counter, and the outputs share The frequencies are connected to the control inputs of the keys. Sources of information taken into account in the examination 1.Boris Ya.V., Krischtal B.V. Quartz digital thermometer. Instruments and systems of control, 1978, no. 12, p. 28.. 2. Malov V.V. Piezoresonance Sensors. ., Energie, 1978, p. 136 (prototep).