SU1276925A1 - Device for measuring temperature - Google Patents

Abstract

The invention relates to temperature measurements and allows the range of measured temperatures to be expanded while reducing the pump signal level. The pump generator 1 emits signals with a frequency equal to the sum of the resonant frequencies of the resonators 2 and 3. In coils 7 and 8, the pump voltage is induced, which through capacitors 5,6 affect the varicap 4, changing its capacitance with the pump frequency. Since the temperature-frequency coefficients of resonators 2 and 3 are opposite in sign, their total frequency does not change much and does not go beyond the range of soft excitation in a wide temperature range even at low pump signal levels. 1 il. 5- ± 1 f s iff 05 with GhE A cl b

Description

The invention relates to temperature measurements, namely, devices for measuring temperature with remote transmission of a signal from a temperature converter to a recording device.

The aim of the invention is to expand the range of measured temperatures while reducing the level of the pump signal by decreasing the drift of the sum frequency of thermo-dependent resonators beyond the range of soft excitation of a parametric oscillator.

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

The device contains a pumping generator 1, a dual-circuit parametric generator including parallel-connected thermo-dependent resonators 2 and 3 and a nonlinear varicap capacitor 4. The resonators are made: on capacitors 5 and 6 and coils 7 and inductance. Radio 9 includes a recorder,

The device works as follows.

 The pump generator 1 emits signals with a frequency equal to the sum of the resonant frequencies of the resonators 2 and 3, the value of which is unambiguously related to the measured temperature. In this case, a pumping voltage is induced in coils 7 and 8, which through capacitors 5 and 6 affects the varicap by changing its capacitance with a frequency of nakaki, which leads to the generation of emitters 2 and 3 at eigenfrequencies. natural frequencies of resonators 2 and 3 or their difference components and the temperature is determined from them.

Since the temperature-frequency coefficients of resonators 2 and 3, Pro Editor A, Lezhnin

Compiled by V. Kulikov

Tehred V. KadarKorrektor l. Patay

Order 6657/33 Circulation 778 Subscription

VNIIPI USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab ,, d, 4/5

Production and printing company, Uzhgorod, st. Project, 4

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76925

opposite in sign, their total frequency varies only slightly and does not exceed the limits of the region of soft excitation in a fairly wide range of temperatures, even with weak pump signal levels. If necessary, in the case of weak pumping (measurements in a liquid conducting medium), resonators 2 and 3 can be chosen with approximately equal absolute values of the coefficients, thereby expanding the range to values characteristic of a high pumping level.

Thermo-dependent resonators of various designs can be used in the device. For example, the device can be implemented on thermowires, one of which uses a ferro-capacitor, which has a decrease in dielectric constant with increasing temperature, and the other has a thermo-dependent inductor on the 3000 MI core, for which the magnetic permeability increases with increasing temperature.

Claims (1)

Claims An apparatus for measuring temperature, comprising a pump generator, a radio receiver with a recorder, and a measuring transducer in the form of a double-circuit parametric generator with non-multiple frequencies, including a first thermal-dependent resonator connected to a varicap output, which is the fact that, in order to expand the range of measured temperatures while reducing the level of the pumping signal, a second thermal-dependent resonator with a temperature-frequency coefficient entom opposite in sign L-temperature coefficient of frequency of the first resonator connected to the terminals of the varicap.