SU1704096A1 - Thermoelectric anemometer - Google Patents

Abstract

The invention relates to a measurement technique and can be used to measure the velocities and flow rates of gases and liquids. The aim of the invention is to increase the sensitivity and reduce the inertia. An anemometer comprising a housing 2, a heater 4, and a semiconductor thermoelectric battery with spans of lead telluride doped with indium and spheres of germanium telluride doped with bismuth are placed on the fairing in the form of a disk with conical planes. When the flow meter flows around the anemometer due to the velocity gradient at the flat fairing, the upper thermopile junctions heat up less than its lower junctions, which leads to an increase in the output signal on the thermopile as the flow rate increases. 3 il.

Description

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The invention relates to a measuring technique and can be used to measure air velocities and gas flows.

The aim of the invention is to increase the sensitivity and decrease the inertia.

FIG. 1-3 shows a diagram of a thermoelectric anemometer.

The anemometer 1 consists of a thin duralumin oxidized case 2 on which polyamide dielectric film 3 is wound, a wire heater 4 with tokovods 5 is placed inside the case, semiconductor thermoelectric connections are deposited onto the dielectric substrate, the p-branch 6 is made of lead telluride, doped indium, switching interlayer 7, p-branch 8 is made of germanium telluride doped with bismuth, contact pads 9. air fairing 10 in the form of a disk with conical planes, body 2 is mounted on the fairing 10 symmetrically with respect to its konusoob- different planes.

The anemometer works as follows.

The anemometer is placed on the air deflector 10 in such a way that, when the air moves, the upper junction flows more around than the lower one. When the heater is turned on in the electric circuit and in the absence of air movement, the emf of the thermopile is zero, since the temperature of the upper and lower junctions is the same. When air moves, the upper junction airflow is greater than from the lower ones, as a result of which a temperature gradient occurs and thermoEMF occurs in the thermopile. proportional to

Flow

the differences T n - T ,, i.e. the temperature differences between the upper and lower spans. The greater the speed of the air; the greater the heat transfer from the upper spa, which leads to an increase in the temperature gradient and. accordingly, an increase in the output signal (E), which is determined by the formula:

E a p + p (Tg - Tu),

where a. thermoelectric coefficient of thermocouple;

p - electronic type of conduction of the thermocouple branch:

p is a hole conductivity type of thermocouple;

T is the temperature of the upper thermopile spa;

Tg is the temperature of the lower thermopile spa.

Thus, the branch velocity or the flow of any non-aggressive gas is measured by the magnitude of the output signal of the thermopower.

Claims (1)

Invention Formula A thermoelectric anemometer, comprising a housing, on the outer surface of which there are flat junctions of a thermoelectric battery and a current source, characterized in that, in order to increase sensitivity and reduce inertia, additionally contains a heater connected to the current source, and a disk with conical planes, the case is installed on the disk symmetrically with respect to its cone-shaped planes, and the heater is inside the case in thermal contact with the joints of the thermoelectric battery, n- and p-junction which They are made of lead telluride doped with indium and germanium telluride doped with bismuth deposited on a dielectric substrate. 676 Fm.z