SU483571A1 - Device for measuring and controlling temperature - Google Patents

Description

Given specific materials and dimensions of the sensor, for example, mm, L 5 lsh, ai-a2 18 10 deg-, S 3,5,

d d

/ g „0.5 AtM, we get -g- 250 10

BUT.

The resolution of the existing tensometric equipment is 2 10. Therefore, the proposed device allows temperature to be measured with an accuracy of up to 0.008 ° C. At the same time, the maximum operating strain of the strain-sensitive wire is 0.7%. Since the pre-tension is equal to half of this value, the ratio between the lengths of the segments of the strain-sensitive wire and the amount of deflection of the bimetallic element is equal to

D 3.5 10-3 or L 280A.

In order to achieve maximum sensitivity, the force developed by the bimetallic element must exceed the value required for stretching the strain gage.

Given this condition, the diameter of the microwire is determined by the formula;

 - 4 .La, -a, fa

 one/

d is the diameter of the microwire;

b - equivalent modulus of elasticity; fj, is the modulus of elasticity.

ten

Subject invention

A device for measuring and controlling temperature, which contains a bimetallic element fixed at one end in a housing and a secondary elastic element that converts the deflection of the bimetallic element into an electrical signal, characterized in that, in order to increase the sensitivity and reliability of the device in operation, the secondary elastic element is designed as included in the interchangeable shoulders of the bridge circuit of two pre-tensioned lengths of strain-sensitive microwires, one ends of which are attached to the movable end of the bimet an element, and others - to the walls of the body.