Metal Oxide Varistor: Zinc Oxide with 0.5 % Chromic Oxide, Bismuth-Manganese Oxide Paste Fired On (Masuyama 1972, Ex. 7)

A varistor whose bismuth oxide and manganese dioxide are both fired on from a paste: 99.5 % zinc oxide with 0.5 % chromic oxide by moles, sintered at 1350 °C, coated with a 70 : 30 bismuth oxide and manganese dioxide paste and fired at 800 °C. The disc measured a C-value of 167 at 1 mA and a nonlinearity exponent n of 34.2. Source: T. Masuyama, M. Matsuoka and T. Nishi (Matsushita), US 3,663,458 (1972), Example 7. Unknown: what the silver paint is, and how strong the epoxy solution of the paste is. The spraying is ours, after US Army Corps of Engineers EM 1110-2-3401 (1999). The 10 g batch is our arithmetic. Picture: the patent's drawing.