| 摘要 |
PROBLEM TO BE SOLVED: To uniformize and stabilize the characteristic of an element at the time of placing an element assembly contg. zinc oxide as the main component and at least a bismuth compd. as the additive component in a closable boxy pot and continuously calcining the assembly at a specified temp. to continuously produce a voltage nonlinear resistor by preventing the defective characteristic in the varistor voltage, clamping voltage ratio, etc. SOLUTION: A boxy pot 1 is used plural times to produce plural lots of an element assembly 5. The pot 1 with the porosity controlled to 5-40% and the weight ratio of the bismuth component in the structure of the pot 1 to <=50wt.%, expressed in terms of Bi2 O3 , is used. Otherwise, the pot with the porosity of its structure controlled to 5-40%, with an impregnated layer 4 filled with a vitreous phase contg. bismuth oxide formed in the pore of the structure of the pot and with the thickness of the impregnated layer controlled to <=70% of the wall thickness of the pot is used. |
