Four things to pay attention to when choosing a Universal thermocouple

Four things to pay attention to when choosing a Universal thermocouple:

Thermocouples are one of the most commonly used components for temperature measurement in the industrial field.

As a commonly used temperature measuring element, thermocouple is often used in conjunction with recording instruments, electronic regulators and many other instruments. Let's take a look at some of the things we need to pay attention to when buying a thermocouple.

1. Selection of measurement accuracy and temperature measurement range

When the operating temperature is 1300~1800℃, and the accuracy is required to be relatively high, the B-type thermocouple is generally used; the accuracy is not high, and the atmosphere allows the use of tungsten-rhenium thermocouples. Above 1800℃, tungsten-rhenium thermocouples are generally used; 1000~1300℃ requires high precision and relatively high temperature. S-type thermocouple and N-type thermocouple are available; K-type thermocouple and N-type thermocouple are generally used below 1000℃, and E-type thermocouple is generally used below 400℃; under 250℃ And negative temperature measurement generally uses T-type thermocouples, which are stable and accurate at low temperatures.

2. The choice of atmosphere

S-type, B-type and K-type thermocouples are suitable for use in strong oxidizing and weak reducing atmospheres. J-type and T-type thermocouples are suitable for weak oxidizing and reducing atmospheres. If a protective tube with better air tightness is used, the Atmosphere requirements are less stringent.

3. Choice of durability and thermal responsiveness

Thermocouples with large wire diameters have good durability, but their response is slower. For thermocouples with large heat capacity, the response is slow. When measuring temperatures with large gradients, the temperature control is poor in the case of temperature control. If the response time is fast and the durability is required, it is more appropriate to choose the armored pair.

4. The nature and state of the measurement object to the selection of the thermocouple

The temperature measurement of moving objects, vibrating objects, and high-pressure containers requires high mechanical strength. The atmosphere with chemical pollution requires a protective tube. In the case of electrical interference, the insulation is required to be relatively high.

Selection process: model - graduation number - explosion-proof grade - accuracy grade - installation and fixed form - protection tube material - length or insertion depth