SU864027A1

SU864027A1 - Temperature measuring device

Info

Publication number: SU864027A1
Application number: SU792843220A
Authority: SU
Inventors: Владимир Леонидович Мухин; Михаил Федорович Кабаков
Original assignee: Омский политехнический институт
Priority date: 1979-11-23
Filing date: 1979-11-23
Publication date: 1981-09-15

Description

Изобретение относится к тепловым измерениям, а именно к устройствам для измерения температуры с бесконтактной передачей сигнала от измерительного преобразователя температуры к регистрирующему устройству. ⁵ The invention relates to thermal measurements, and in particular to devices for measuring temperature with non-contact signal transmission from a temperature measuring transducer to a recording device. ⁵

Известно устройство для измерения температуры, содержащее датчик температуры, индуктивно связанный с генератором Ц].A device for measuring temperature, containing a temperature sensor inductively coupled to the generator C].

Однако это устройство имеет ограниченное пространственное разделение генерато-¹⁰ра с датчиком температуры из-за необходимости сильной связи между контуром генератора и контуром датчика. Использование схемы с затягиванием частоты ограничивает точность таких устройств изза присущей этой схеме невысокой стабильности частоты.However, this device has a limited spatial separation of the generator ¹⁰ with the temperature sensor due to the need for strong coupling between the generator circuit and the sensor circuit. The use of a frequency pull-up circuit limits the accuracy of such devices due to the inherent low frequency stability in this circuit.

Известно устройство для измерения температуры, содержащее в качестве датчик температуры термочувствительный пьезорезонатор, включенный в схему генератора прямоугольных импульсов t2j.A known device for measuring temperature, containing as a temperature sensor a thermosensitive piezoresonator included in the circuit of the square-wave generator t2j.

Недостатком устройства является низкая точность измерения температуры.The disadvantage of this device is the low accuracy of temperature measurement.

Наиболее близким по технической сущности к предлагаемому является устройство Для измерения температуры, содержащее термозависимый пьезорезонатор в качестве датчика температуры. включенный в част отноза дающую цепь измерительного преобразователя, радиоприемник с регистратором. В этом устройстве пьезорезонатор включен в измерительный преобразователь, содержащий автогенератор, источник питания. Радиосигнал с частотой равной частоте пьезорезонагора излучается генератором, принимается приемником и фиксируется регистратором, например частотомером Га}.The closest in technical essence to the proposed is a device for measuring temperature, containing a temperature-dependent piezoresonator as a temperature sensor. a radio receiver with a recorder, which is included in the partly related circuit of the measuring transducer. In this device, the piezoresonator is included in the measuring transducer containing the oscillator, a power source. A radio signal with a frequency equal to the frequency of the piezoresonator is emitted by a generator, received by a receiver, and recorded by a recorder, for example, a frequency meter Ha}.

Недостатком устройства является узкий диапазон измеряемых .температур, который ограничен рабочими температурами источника питания. Кроме того, погрешность измерения температуры этим устройством возрастает с понижением абсолютного значения температуры вследствие выделения тепла схемой автогенератора, причем основная часть мощности выде-4 ляется в виде тепла активным элементом. Это особенно существенно в диапазоне криогенных температур. ₅ The disadvantage of this device is the narrow range of measured temperatures, which is limited by the operating temperature of the power source. In addition, the temperature measurement error with this device increases with decreasing absolute temperature due to heat generation by the oscillator circuit, and the main part of the power is released as heat by the active element. This is especially significant in the range of cryogenic temperatures. ₅

Цель изобретения - расширение диапазона измерения, а также повышение точности измерения температур.The purpose of the invention is the expansion of the measuring range, as well as improving the accuracy of temperature measurement.

Поставленная цель достигается тем, что в устройство для измерения темпера- ₁₀туры введен генератор накачки для возбуждения измерительного преобразователя, а измерительный преобразователь выполнен в виде двухконтурного параметрического генератора с некратными часто— ₁₅та ми.The goal is achieved in that the device for measuring the temperature of the pump ₁₀ tours introduced generator for exciting the transducer, and the transducer is in the form of a bypass parametric oscillator ₁₅ with the frequency that nonmultiple mi.

На чертеже представлена функциональная схема устройства для измерения температуры с одним из вариантов измерительного преобразователя - схема двухконгуриого параметрического генератора (ДПГ).The drawing shows a functional diagram of a device for measuring temperature with one of the variants of the measuring transducer - a circuit of a two-parametric parametric generator (DPG).

Устройство содержит генератор накачки 1, двухконтурный параметрический генератор, включающий термозависимый пьезоре— зонатор 2, параллельно которому включены ₂₅варикап 3 и колебательный контур, образованный емкостью 4 и индуктивностью 5, радиоприемник 6, в состав которого входит регистратор.The device contains a pump generator 1, a dual-circuit parametric generator, including a thermally dependent piezoelectric resonator 2, parallel to which ₂₅ varicaps 3 and an oscillating circuit formed by a capacitance 4 and inductance 5, a radio receiver 6, which includes a recorder, are included.

Устройство работает следующим образом.The device operates as follows.

Генератор накачки излучает сигнал, частота которого'определяется соотношением £_н , где - резонансная частота пьезорезонатора резонансная частота контура, образованного элемента- ³⁵ми 4 и 5.The pump generator emits a signal whose frequency is determined by the relation £ _n , where is the resonant frequency of the piezoresonator, the resonant frequency of the circuit formed by the elements ³⁵ and 4.

В катушке индуктивности 5 наводится напряжение с частотой сигнала накачки £_н, которое через конденсатор 4 воздействует на варикап 3 и изменяет его емкость с частотой накачки. Изменение емкости связи двух колебательных контуров приводит к возникновению генерации на собственных частотах этих контуров. Поскольку частота накачки постоянна (стабилизирована), изменение резонансной частоты термозависимого пьезорезонагора приводит к изменению второй генерируемой частоты ДПГ при воздействии температуры. Следовательно, о температуре можно судить по значению любой из генерируемых частот, либо по их разрядности.In the inductor 5, a voltage with a frequency of the pump signal £ _n is induced, which through the capacitor 4 acts on the varicap 3 and changes its capacitance with the pump frequency. A change in the coupling capacitance of two oscillatory circuits leads to the generation of these circuits at the natural frequencies. Since the pump frequency is constant (stabilized), a change in the resonant frequency of the thermally dependent piezoresonator leads to a change in the second generated frequency of the DPG when exposed to temperature. Therefore, the temperature can be judged by the value of any of the generated frequencies, or by their bit depth.

Вследствие сильной нелинейности, обусловленной· нелинейностью вольт-фар адной характеристикой варикапа, через катушку индуктивности 5 колебательного контура протекают составляющие токов с частотами £_л . £& , £ц ,£_л-£цИ т.д. Протекающие токи создают электромагнитное поле, принимаемое радиоприемником 6, настроенным на частоту £¢,, либо на разность генерируемых частот Г =£,- £г^.Due to the strong nonlinearity caused by the nonlinearity of the volt-headlight characteristic of the varicap, current components with frequencies £ _l flow through the inductor 5 of the oscillating circuit. £ &, £ q, £ _l - £ qi etc. The flowing currents create an electromagnetic field received by the radio receiver 6 tuned to the frequency £ ¢, or to the difference in the generated frequencies Γ =,, - г r ^.

Выбирая £^= K£q, где К - иррациональное число большее единицы,, можно повысить чувствительность устройства в К раз, при приеме радиоприемником сигнала с частотой или в 2^/F раз, если радиоприемником принимается сигнал с частотой F.Choosing £ ^ = K £ q, where K is an irrational number greater than unity, it is possible to increase the sensitivity of the device by a factor of K when a signal is received by a radio receiver with a frequency or by 2 ^ / F times if a signal with a frequency F is received by a radio receiver.

Отсутствие источника питания в измерительном преобразователе расширяет диапазон измеряемых температур вплоть до криогенных температур, уменьшает его размеры, повышает надежность.The absence of a power source in the measuring transducer extends the range of measured temperatures up to cryogenic temperatures, reduces its size, and increases reliability.

Использование параметрического генератора для возбуждения пьезорезонатора позволяет также минимизировать мощность от тепловыделения автогенератора, а следовательно, и погрешность измерения температуры из-за этой мощности, что особенно важно в диапазоне криогенных температур.The use of a parametric generator to excite the piezoresonator also allows minimizing the power from the heat generation of the oscillator, and hence the error in temperature measurement due to this power, which is especially important in the cryogenic temperature range.

Claims

The image is ognosigs to thermal measurements, namely to temperature measuring devices with contactless signal transmission from a temperature measuring transducer to a recording device. A device for measuring temperature is known, comprising a temperature sensor inductively coupled to a D-generator. However, this device has a limited phosphorus separation of the generator with a temperature sensor due to the need for a strong connection between the generator circuit and the sensor circuit. The use of a circuit with frequency clamping limits the accuracy of such devices due to the inherent frequency stability of this circuit. A device for temperature measurement is known, which contains a temperature-sensitive piezoresonator as a temperature sensor, which is included in the G23 impulse generator circuit. A disadvantage of the device is the low temperature measurement accuracy. The closest in technical essence to the present invention is a device for measuring temperature, comprising a thermally dependent piezoresonator as a temperature sensor. included in the measuring circuit part of the transmitter, a radio receiver with a recorder. In this device, a piezoresonator is included in a measuring transducer containing an auto-oscillator, a power source. A radio signal with a frequency equal to the frequency of the piezoresonator is radiated by a generator, received by the receiver and recorded by a recorder, for example, a Gz frequency meter. The drawback of the device is the narrow range of measured temperatures, which is limited by the operating temperatures of the power source. In addition, the error in measuring the temperature of this device increases with a decrease in the absolute value of the temperature due to the release of a grill by an autogenerator circuit, and 1x; most of the power output goes in the form of heat as an active element. This is especially significant in the range of cryogenic gemperagur. The purpose of the invention is the extension of the measuring range, as well as an increase in the accuracy of temperature intention. This goal is achieved by introducing a pump exciter into the temperature measuring device to excite the measuring transducer, and the measuring transducer is designed as a dual-circuit parametric oscillator with non-multiple frequencies. The drawing shows a functional diagram of a device for measuring temperature with one of the variants of a measuring converter - a dual-circuit parametric oscillator circuit (DLG. The device contains a pump 1 generator, a dual-circuit parametric generator including a thermo-dependent piezoresonator 2, in parallel with which varicap 3 is connected and an oscillatory circuit formed by capacitance 4 and inductance 5, the radio receiver 6, which includes the recorder. The device works as follows. The pump generator The signal is emitted, the frequency of which is determined by the ratio, where / 1 is the resonant frequency of the piezoresonator 2; {|. is the resonant frequency of the circuit formed by elements 4 and 5. In the inductance 5, a voltage is induced with the frequency of the pump signal {which through the capacitor 4 acts It changes the capacitance of the two oscillatory circuits to the generation of the natural frequencies of these circuits. Since the pumping frequency is constant (stabilized), a change in the resonant frequency of a thermo-dependent piezoresgator leads to a change in the frequency of the generated frequency € (1 DPG when exposed to temperature. Therefore, the temperature can be judged by the value / beat from the generated frequencies, or by their size. Due to the strong nonlinearity, the “1H” condition of the non-linearity of the voltage-capacitance characteristic of the varicap, the components of currents with frequencies, f 2, c, etc. flow through the inductance 5 of the oscillating circuit The electromagnetic field received by the radio receiver b tuned to the frequency ffjL or the difference of the generated frequencies P € -, Q .. is chosen. Choosing where K is an irrational number greater than one, the device can be increased in K times when the radio receiver receives a signal with frequency 5, -j or times, if the signal is received by the radio receiver with frequency F. The absence of a power source in the measuring transducer expands the range of measured temperatures up to cryogenic temperatures, reduces its size, increases reliability. The use of a parametric rekagora to excite the piezoresonate also minimizes the power from the thermal gap of the oscillator, and consequently, the error in temperature measurement due to this power, which is especially important in the range of cryogenic temperatures. The invention The device for measuring temperature, containing a thermo-dependent piezoresonator as a temperature sensor, is inserted into the frequency-setting circuit of the measuring transducer, a radio receiver with a recorder that differs from that in order to extend the measuring range, a pump generator is introduced into it to excite the measuring preofazovatel, and the measuring transform is made in the form of a dual-circuit parametric generator with non-multiple frequencies. Sources of information taken into account during the examination 1. USSR author's certificate No. 127842, cl. Q 01 K 7/32, 1959.

2. USSR author's certificate number 193754, cl. Q O1 C 7/32, 1965.

3. Golembo, VA and others. Piezokvartsovye analog temperature transducers. Lviv, Vishcha school, 1977, p. 23, fig. 2.3g (prototype).