How to detect the quality of a heating tube?

How to detect the quality of a heating tube? The use of heating tubes is also the most common in equipment that needs to be heated. However, in the event of heating tube failure without heating, what should we do and how to determine whether the heating tube is good or bad? Below, Subot Technology will explain in detail several methods for detecting whether the heating tube is good or bad.
1. Using a multimeter resistance range to measure resistance is sufficient. A few ohms to tens of ohms is good, and even a few thousand ohms or even higher is bad.
2. Calculate the resistance of the heating tube based on the voltage and the design power of the heating tube. The formula is R=(V x V)/P (R represents resistance, V represents voltage, and P represents power). If the result is greater than 0 but less than 1000, it is good.
3. Therefore, use the Ohm range of a multimeter（ × When measuring, if the reading is infinite or close to infinity, it is considered an open circuit. A reading indicates that it is normal and not damaged.
4. When the electric heating tube is not energized, observe whether there are obvious holes, sand holes, cracks, and tube explosions on the surface of the tube. If not, it is generally good. If the above imagination does not exist but can still be used, then the 1.2.3 method can be used for testing.
Judgment method for heating tube: If there are obvious holes, sand holes, cracks, and tube explosions on the surface of the tube, it indicates that the heating tube has been damaged and cannot be used normally; When the measured resistance value is zero, it also indicates that the heating tube cannot be used; If the surface is intact and the resistance value is within the normal range, then other reasons need to be found.