How to detect the quality of a heating tube?
1. Use a multimeter to measure the resistance. A few ohms to tens of ohms are good, and thousands of ohms or even higher are bad.
2. Calculate the resistance of the heating tube by the voltage and the design power of the heating tube. The formula for the resistance of the heating tube is R = (V x V) / P (R stands for resistance, V stands for voltage, and P stands for power). The result is greater than 0 and less than 1000. OK.
3. Therefore, when measuring with the multimeter's ohm range (×10Ω), if the reading is infinity or close to infinity, it is 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, trachoma, cracking and bursting on the surface of the tube. If it is not, it is generally good. If the above imagination does not exist but it can be used, then you can use section 1.2. 3 methods of testing.
Heating tube judgment method: If there are obvious holes, trachoma, cracking and tube explosion on the surface of the tube, it means that the heating tube has been damaged and can no longer be used normally;. when the measured resistance value is zero, it also means that the heating tube cannot be used; if the surface is intact , The resistance value is within the normal range, then you need to find other reasons.