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Thermocouples are widely used, but the most important thing when we purchase or sell is how to choose a thermocouple !
Choosing a thermocouple should be based on a comprehensive consideration of the operating temperature range, the required accuracy, the operating atmosphere, the performance of the measurement object, the response time, and economic benefits.
1.Selection of measurement accuracy and temperature measurement range
When the operating temperature is 1300 ~ 1800 ℃, and the accuracy is relatively high, a B-type thermocouple is generally used; if the accuracy is not high, the tungsten-rhenium thermocouple can be used in the atmosphere, and the tungsten-rhenium thermocouple is generally used above 1800 ℃; 1000 ~ 1300 ℃ requires high accuracy and available S-type thermocouple and N-type thermocouple ; K-type thermocouple and N-type thermocouple are generally used below 1000 ℃, and E-type thermocouple is generally used below 400 ℃; at 250 ℃ And negative temperature measurement generally uses T-type thermocouples, T-type thermocouples are stable and accurate at low temperatures.
Choice of using atmosphere
S type, B type, and K type thermocouples are suitable for use in strong oxidation and weak reducing atmospheres, and J type and T type thermocouples are suitable for use in weak oxidation and reducing atmospheres. If a protective tube with better air tightness is used, Atmosphere requirements are less stringent.
3. Choice of durability and thermal response
A thermocouple with a large wire diameter has good durability but a slower response. For a thermocouple with a large thermal capacity, the response is slow. When measuring a temperature with a large gradient, the temperature control is poor in the case of temperature control. It requires fast response time and a certain durability, so it is more appropriate to choose armored couples.
4.The nature and status of the measurement object
The temperature measurement of moving objects, vibrating objects, and high-pressure vessels requires high mechanical strength, a chemically contaminated atmosphere requires a protective tube, and electrical insulation requires high insulation.
Selection process: model--index number--explosion-proof grade--precision grade--installation and fixing form--protective tube material--length or insertion depth
Thermocouple selection and ordering instructions:
1. Please indicate when selecting and ordering
2 Product model
2 Protection tube material and diameter
2 Protection tube total length L and insertion depth I
2 Fixture type
2 Product actual measurement range
2. Threaded fixing device types are not marked with fixed external thread M27 × 2 when ordering (the remaining types of threaded fixing types must be specified)
3. If the product does not match the above product model due to the special needs of the user, a specially manufactured product is required. Please indicate your special technical requirements and contact (or write) the relevant responsible department of our company for special orders. Specific consultation: 0517-86900920