Spring principle is to rely on bimetallic thermometer sensors principle of heat bilges cold shrink, through the thermal probe behind the thermometer readings to contact with the metal surface to be tested. This type of double metal surface thermometer can range from - 40 c to 500 c, the precision can be in for some using occasions for accuracy is not high, can yet be regarded as a money and cheap thermometer of beauty. Spring thermometer how to install in the line? Spring is one of the surface thermometer thermometer, it USES spring is fixed on the pipeline installation, spring type surface thermometer when use should pay attention to the length of the spring and the diameter to be fixed. Instrument to introduce the spring thermometer below for your reference: ST221SS a thermometer, product name: spring thermometer, pointer thermometer, pipe, surface thermometer thermometer, industrial thermometer use areas: pipes, surface, industrial, petroleum, chemical industry, power plants, Marine, specifications, such as description: models: ST221SS types: pipeline thermometer, surface thermometer structure: axial type, spring type fixed ring on the cover: pressure BianShi material: stainless steel shell, the copper connection tooth head: no teeth, behind a word adjustable surface diameter: 63 mm temperature range: 0 - 120C( Can be customized) Accuracy: & plusmn; Table: 3% glass protection grade: IP55 ( Dust, water) Can be fixed within 50 mm line 4, the product features: the spring scene shows temperature thermometer, spring is fixed, intuitive and convenient; Safe and reliable, long life, fast reading. Fifth, use note: the spring type surface thermometer again to pay attention to when using the length of the spring and the diameter to be fixed. In addition, when using, pay attention to clean up and check, regularly test the measured values. Six, the service is introduced: this product is used in pipelines, chemical equipment, used to measure the surface temperature, special thermometer is pipes.