Bimetallic thermometer theoretical knowledge

For just entering and preparation for entering instrumentation industry, may be the bimetallic thermometer is not too can understand, we saw most is just a thermometer, it is also one of the types of thermometer. Below we'll introduce what is bimetallic thermometer, it is to use two different temperature expansion coefficient of metal, in order to improve the temperature measuring sensitivity, is usually made of metal spiral coil shape, when two layers of metal temperature change, the layers of metal expansion or contraction, makes the spiral coil rolled up or let go. As a result of the spiral coil end fixed and the other end connected to a free rotating pointer, therefore, when the bimetallic strip feel the temperature change, Pointers can be on the panel dividing scale to indicate the temperature. After you know this principle, it is no more clear understanding of the bimetallic thermometer. Below we will introduce bimetallic thermometer components, such as the axial thermometer, it is composed of panel/table cover/pan/heat pipe/pointer/joint/double metal sensors/size of the gear. How does it work? Bimetallic thermometer is a round shape into threaded heat bimetallic strip as thermal devices, and put it in a protective sleeve tube, one end is fixed, known as the fixed end, the other end of the connection on a thin shaft, a free end. Spool at the free end is equipped with a pointer. When the temperature changes, the resulting thermal devices the free end of the rotation, drive the thin axis from the Angle of the pointer changes, the corresponding temperature indicator on the dial; Straight table by steering transmission mechanism drive the pointer changes. Due to the thermal device has a linear relation with temperature changes, so the position of the pointer indicated by bimetallic temperature sensor, that is, the temperature of the measured values. The instrument of temperature measurement range is 0 ℃ - 120 ℃, the permissible error of scale range of 1. 5%.