On 2018-08-08 14:48:54
Composition of thermal resistance temperature measurement system
1) the thermal resistance temperature measurement system is generally composed of thermal resistance, connecting wire, display instrument, etc. The following two points must be noted:
The graduation number of thermal resistance and display instrument must be the same.
In order to eliminate the influence of the change of the resistance of the connecting wire, the three wire connection method must be adopted.
2) thermal resistance is a solid body composed of temperature sensing element (resistance body), lead wire, insulating material and stainless steel sleeve. Its outer diameter is generally φ 1 ~ φ 8mm, and Zui can be up to φ mm. Compared with the ordinary thermistor, it has the following advantages:
Small volume, no air gap inside, small measurement lag in thermal inertia;
Good mechanical properties, vibration resistance, impact resistance;
Can be bent, easy to install
Long service life.
3) the end thermal resistance end thermal resistance temperature sensing element is made of specially processed resistance wire, which is close to the end surface of the thermometer. Compared with the general axial thermal resistance, it can more accurately and quickly reflect the actual temperature of the measured end face, which is suitable for measuring the end face temperature of bearing shells and other parts.
4) the explosion-proof type of thermal resistance shall pass through the junction box with special structure, and the explosive gas mixture inside the shell will inevitably change the length of the resistance wire and affect the resistance value due to the open circuit repair of the resistance body such as spark or arc. Therefore, it is better to replace the resistance body with a new one. If the welding repair is adopted, it can only be used after the verification is qualified.