Precision of high temperature resistance furnace

High-temperature resistance furnaces are widely used in cement plants, pharmaceutical plants, and various laboratories, and ensuring the accuracy of their temperature measurement is crucial for the stability of the production process and the reliability of experimental results. The temperature control of a high-temperature resistance furnace relies on the measurement and feedback of thermocouples and display instruments, so ensuring the accuracy of the temperature measurement system needs to be strictly controlled at every step, from selection and installation to periodic verification.

Equipment and accessories

Choosing the right high-temperature resistance furnace, thermocouple and display instrument is the basis for ensuring accurate temperature measurement. When selecting, the temperature range to be measured, the tolerance for error, and the required temperature recording and control functions must be considered.

Choosing a thermocouple type – The type and size of a thermocouple directly affects the accuracy of the measurement results. According to the working environment of the high-temperature resistance furnace and the nature of the medium to be measured, select the appropriate thermocouple type (such as platinum rhodium thermocouple, nickel-chromium thermocouple, etc.) and graduation number to ensure its reliability within the operating temperature range.

Choose the right display – The display should be accurate enough and its measurement range should be as close as possible to the actual operating temperature to improve the accuracy of the readings. At the same time, the installation environment of the instrument also needs to be considered, such as avoiding vibration sources and excessive humidity.

Proper use and installation

The correct use of high-temperature resistance furnaces and the correct installation of thermocouples are the key to ensure the accuracy of temperature measurement.

How it works: The working principle of a high-temperature resistance furnace involves the deviation between the temperature sensed by the thermocouple and the set temperature, and the thermostat adjusts the heating power according to this deviation to maintain a constant temperature. During installation, it is necessary to ensure that the temperature of the thermocouple's reference end is in a temperature-stable region to avoid interference from heat sources.

Proper installation of thermocouples

   Location selection – Thermocouples should be inserted into the appropriate location in the furnace to ensure an accurate reflection of the temperature being measured. The thermocouple should be inserted 8-10 times the diameter of the sheath and as close as possible to the object being measured.

   Protection measures - the gap between the protective tube of the thermocouple and the furnace wall needs to be blocked with refractory materials or asbestos ropes to avoid the convection of air in the hot and cold chambers affecting the accuracy of temperature measurement.

Periodic verification and on-site calibration

In order to ensure the continuous and stable operation of the high-temperature resistance furnace and to maintain the accuracy of the high-temperature measurement, regular verification and on-site calibration must be carried out.

Verification of thermocouples and display instruments

   When performing thermocouple verification, care needs to be taken to correct the reference temperature and ensure that the standard thermocouple is protected from gas corrosion.

   Attention should be paid to the temperature distribution in the furnace to ensure the accuracy of the thermocouple verification results.

On-site calibration

   Use a standard thermocouple and a standard DC potentiometer or data collector to check the accuracy of the thermocouple and thermostat temperature measurement system to ensure that the overall system error is within acceptable limits.

summary

The temperature measurement accuracy of the high-temperature resistance furnace is directly related to the efficiency of the production process and the reliability of the experimental results. In order to ensure the accuracy of the temperature measurement system, it must be strictly controlled from equipment selection, installation, use to regular verification. Correct selection of equipment and accessories, reasonable installation of thermocouples and regular calibration will effectively improve the measurement accuracy and ensure the reliability and stability of the high-temperature resistance furnace in actual operation.