What kind of thermometer to measure the low temperature of 40 ℃ below zero

A lot of thermometer measurement minus 40 ℃, is our common bimetallic thermometer, it is a kind of measurement in the field of low temperature test instrument. Can be directly measured in the process of various production - 80℃- Liquid + 500 ℃ range steam and gas medium temperature. Bimetallic thermometer is mainly used in industry of element is one with two or more pieces of metal laminate composed of multilayer metal together, using two different metal working in the principle of expansion degree of different temperature changes. Is based on the ring around made of bent bimetallic strip. End is heated expands, turns the pointer, the instrument will show thermoelectric potential should value. We A300C, for example, about to minus 40 ℃ low temperature measurement of some of the specifications of the bimetallic thermometer. Structure: universal type cover circle: flange type, tray type panel material: stainless steel SS304 tooth head: 1/2 & quot; NPT other optional surface diameter: 80 mm heat pipe diameter: 6. 35 mm heat pipe length: 150 mm ( 50 - Optional) around 2000 mm. Temperature range: - 40+80C ( Can be customized) Accuracy: & plusmn; 1. Table: 5% glass protection grade: IP65 ( Dust, water)