Test project            1. The appearance and visual inspection of the products under the lamp are normal.            2. Dimension, caliper, according to the drawing direct measurement, product no abnormal.            3. The heating resistance value is directly measured by DC resistance tester            4. Resistance temperature coefficient (TCR), measure the resistance value R1 of T1 (25 ℃), put the product wiring into the box furnace, set T2 (800 ℃), after the temperature is stable, measure the resistance value R2 at 800 ℃. TCR = (r2-r1) / R1 (t2-t1)            5. Insulation resistance, withstand voltage, put the ceramic heating plate into the water, the electrode point is 8mm higher than the water surface. The applied voltage is measured, and the product is normal.            6. Dry firing and power on test            Put the ceramic heating plate into the dry firing and power on test bench, 220 V, 1 min, and the product appearance and resistance are normal.

performance requirement             Serial number performance test conditions requirements            1. Working voltage: 220 V            2. Heating resistance value / power, dry firing in air 51 ohm / 950W            3. Temperature coefficient of resistance (TCR) 0-800 ℃ 3800 ± 300 ppm / ℃            4. Insulation resistance: DC500v > 100m Ω,            5. Withstand voltage: ac2500v, 1s breakdown current ≤ 5mA,