The difference between bimetal thermometer and platinum resistance thermometer

The main component of an industrial bimetal thermometer is a multilayer metal sheet composed of two or more metal sheets laminated together. In order to improve the sensitivity of temperature measurement, the metal sheet is usually made into a spiral shape. When the temperature of the multi-layer metal sheet changes, the amount of expansion or contraction of each layer of metal varies, causing the spiral coil to roll up or loosen. Because one end of the spiral coil is fixed and the other end and a bimetallic thermometer can be used from industry, the main component is a multilayer metal sheet composed of two or more metal sheets laminated together. In order to improve the sensitivity of temperature measurement, the metal sheet is usually made into a spiral shape. When the temperature of the multi-layer metal sheet changes, the amount of expansion or contraction of each layer of metal varies, causing the spiral coil to roll up or loosen. Because one end of the spiral coil is fixed and the other end is connected with a pointer that can rotate freely, when the bimetallic piece feels the temperature change, the pointer can indicate the temperature on a circular graduation scale. The temperature measurement range of this kind of instrument is 200~650℃, and the allowable error is about 1% of the two steps of the scale. The purpose of this thermometer is similar to that of a rod-shaped glass liquid thermometer, but it can be used under conditions that require higher mechanical strength. WSS series bimetal thermometer is an on-site detection instrument suitable for measuring medium and low temperature. It can be used to directly measure the temperature of gas, liquid and steam. The thermometer is waterproof, anti-corrosion, vibration-resistant, intuitive and easy in terms of design principle and structure. Features such as reading, no mercury hazard, sturdiness and durability. It can replace other temperature measuring instruments and is widely used in petroleum, chemical, machinery, shipbuilding, power generation, textile, printing and dyeing industries and scientific research departments. Bimetallic thermometers are manufactured using the principle that different metal sheets pressed together will cause bending due to the different expansion coefficients of the two metals after being heated. The greater the temperature change, the more severe the bending. Converting it to a pointer value is a thermometer. The platinum resistance thermometer is manufactured using the principle that the resistance of metal platinum increases with the increase in temperature, and then converted into a readable value by an electronic circuit, which has higher accuracy than bimetal thermometers.