SU27315A1 - Instrument for transmitting the temperature change reading - Google Patents

Description

The invention relates to a device that serves to transmit, over a distance, indicators of temperature change in various kinds of rooms. The main part of the device is a tension oscillating string, the oscillation frequency of which varies with temperature. To change the tension of the string, a system of bimetallic rods that is bent with a change in temperature is used.

H drawing FIG. 1 and 2 schematically depict the device in two projections.

The proposed device consists of U-shaped bimetallic rods 1 and 2, forming the device's am. The string 3 is fastened between the free ends of the rods, and its fastening is made by means of a tension device, which allows the tension of the string to be adjusted during adjustment of the device. Near the string there is an electromagnet 4 fed at changes in the current of varying frequency in order to excite the vibrations of the string. Naturally, the string will oscillate (sound) only when the frequency of the current supplying the clog solenoid 4 is equal to the frequency of the natural oscillations of the string. The moment of onset of resonance can be determined in various ways, one of which is the envisaged

in this case, the resonance method. For the latter purpose, there is a microphone 5 fixed near the string connected to the telephone.

With the help of this device one can make measurements, of course, only after preliminary calibration of it to the temperature. Calibration is carried out by placing the device in a thermostat with a variable temperature, and at each of its values the frequency of the current causing resonant oscillations is determined using connected strings.

The sensitivity of the instrument can be made arbitrarily large by proper selection of the basic system dimensions and materials for the rods. To obtain the greatest accuracy, one system of rods is made, for example, from Invar, the other is made from aluminum, and accordingly the length of the rods increases. For the device shown in the drawing, according to the authors, the measurement accuracy is seventy oscillations of 1 ° with an initial system of 1000 oscillations, which corresponds to an accuracy of the order of 0.01-0.02 °.

The subject matter of the invention.

Instrument for transmitting the temperature change reading

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using expansion of rods connected in a rigid system and made of materials with different coefficients, free, the ends of which are displaced, are relative to one another with temperature changes, characterized in that -.

-: 2

The captivity is located in front of the electromagnet 4 string 3, whose natural frequency when changing its tension due to a change in temperature is determined by one of the existing methods, for example, by the method of resonance.

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