Wegner & Bretschneider
Resistor composition for resistor-incorporated spark plugs
 A resistor composition for a resistor-incorporated spark plug, composed of glass, an inorganic aggregate and carbon, and adapted to be sealed in a centerbore in a ceramic insulator, at least 1% by weight of said aggregate being in advance mixed and calcined with an organic carbonaceous material to adsorb resultant carbonized carbon. 
NGK Spark Plug Co., Ltd.
H
H01T
inventional
Yasuhiko Masao Makoto
Suzuki Sakai Sugimoto