SU581400A1

SU581400A1 - Electrothermoanemometric pressure drop transducer

Info

Publication number: SU581400A1
Application number: SU7502091177A
Authority: SU
Inventors: Борис Федорович Шкурко; Виктор Васильевич Перепелкин; Федор Львович Попов
Original assignee: Военно-Инженерная Ордена Ленина Краснознаменная Академия Им. В.В.Куйбышева
Priority date: 1975-01-02
Filing date: 1975-01-02
Publication date: 1977-11-25

Description

1one

kИзобретение относитс к области приборорйбор строени , в частности, к устройствам измерени перепада давлений.The invention relates to the field of instrumentation, in particular, to devices for measuring pressure differential.

Известны термоанемомет|)ические преобразователи перепада давлений, содержащие терморезисторы , расположенные в воздухопроводном канале с диафрагмой. Известн 1е устройства требуют индивидуального отбора характеристик терморезисторов .Thermo-anemometer are known. |) Pressure transducers with pressure transducers containing thermistors located in the air duct with a diaphragm. Known 1st devices require individual selection of the characteristics of thermistors.

Наиболее близким по техни еской сущности и достигаемому эффекту к предлагаемому устройству вл етс устройство, содержащее воздухопроводный канал, два термистора с двум диафрагмами, заградительную заслонку и две электроизмерительные мостовые схемы с источииками питани (2.The closest in technical essence and effect achieved to the proposed device is a device containing an air duct, two thermistors with two diaphragms, a barrier valve and two electrical bridge circuits with power supplies (2.

Цель предлагаемого устройства - повышение надежности.The purpose of the proposed device is to increase reliability.

Это достигаетс тем, что устройство, содержащее дватермистора, установленные в противоположных концах воздухопроводного канала с двум диафрагмами, заградительиую заслонку и две электроизмерительные мостовые схемы с источниками питани , дополнительно введена заградительна заслонка, при этом заслонки расположены в противоположных концах воздухопроводного канала, а каждый термйстор расположен между диафрагмой и заградите ьйой заслонкой.This is achieved by the fact that a device containing a dual driver, installed at opposite ends of the air duct with two diaphragms, a barrier valve and two electrical bridge circuits with power sources, is additionally introduced a barrier valve, with the flaps located at opposite ends of the air duct channel, and each thermistor is located between the diaphragm and the rear flap.

На че()теже показана функциональна схема предлагаемого преобразовател .On Che (), the functional diagram of the proposed converter is shown.

Преоб{)азователь содержит воздухопроводный канал 1, по которому проходит поток боздуха одной температуры, термисторы 2 и 3, подогреваемые током, диафрагмы 4 и 5, формирующие узконаправленную струю воздуха дл охлаждени термисторов 2 и 3, заградительИЬё заслонкн 6 и 7 дл снижени скорости потока воздуха, электроизмерительные мостовЫе схемы 8 и 9, регистрирующее устройство 10 перепада давлени и источник П питани .The transformer contains a duct channel 1 through which the flow of air at the same temperature, thermistors 2 and 3, heated by current, diaphragms 4 and 5, forming a narrowly directed air stream for cooling thermistors 2 and 3, blocking the dampers 6 and 7 to reduce the flow rate air, electric bridges and circuits 8 and 9, a differential pressure recording device 10 and a source of power supply.

Преобразователь работает следующим образоМ .The converter works as follows.

Claims

Pr air pressure P i, greater than pressure P2, will be transmitted by air flowing through the air duct I from the inlet cavity with pressure P (to the output cavity with pressure Pg. When air flows, diaphragm 4 forms a narrowly directed jet to the thermistor 2 body that cools it. After the thermistor 2 has cooled, the jet is broken up by covering it with a full damper 6 and then passing through a larger volume of channel 1 at a much slower speed.Further, a stream of air flows around the barrier valve 7, the receiving body of thermistor 3 and the output t through the opening of the diaphragm 5 to another room. Since the focused air flow to the receiving body of thermistor 2 has a much higher speed and, therefore, provides a greater cooling intensity than the air flow over the body of thermistor 3, the electrical resistance of the thermistor 2 will change larger than the thermistor 3. As a result, the unbalance of the electric measuring bridge 8 will be greater than the unbalance "Osta 9, and hence the potential difference in the diagonal of the bridge 8 will be greater than the potential difference In the diagonal of the bridge 9. Since the bridge circuits are interconnected counter, the recording device 10 will fix the difference in voltage between them. The polarity of the recorded voltage will be determined by the polarity of the voltage in the diagonal of the bridge 8. With an increase in pressure drop (at Р | Р), the voltage increase in the diagonal of the bridge 8 will always be greater than the voltage increase in the diagonal of the bridge 9. A similar physical process occur at reverse pressure drop, i.e., when P) Pr, but in this case the polarity of the voltage being detected will be determined, with a voltage multiplicity in the diagonal of the bridge 9. Invention formula pressure, containing two thermistors installed at opposite ends of the air duct with two diaphragms, a barrier valve and two electrical bridge circuits with power sources, characterized in that, in order to increase reliability, a barrier valve is inserted, while the valves are located at opposite ends of the air pipeline channel, and each thermistor is located between the diaphragm and the barrier valve. Sources of information accepted in heed 1. USSR author's certificate number 365607, class: G 01 L 13/06, 1970.

2.Ferets V. А. Semiconductor jet thermoanemometers. “Energie, 1972, p. 14, fig. 1 - 4a.

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