| 摘要 |
PROBLEM TO BE SOLVED: To provide a spark plug with small dispersion of resistance values of a resistor and stable load life characteristics after assembled to prevent the generation of electric wave noise. SOLUTION: In a spark plug 100, a resistor 15 is constituted as a sintered body formed by sintering a mixture of glass powder and conductive material powder. The glass powder contains fine glass having a particle size of 100μm or less and coarse glass having a particle size of 100-800μm, and the ratio Wf/Wc of the weight Wf of the fine glass to the weight Wc of the coarse glass is set in the range of 2/98-50/50. The particle distribution of the coarse glass is specified such that when the total weight of the coarse glass is 100wt.%, the content ratio of particles having a particle size of 100-248μm is 10-60wt.%, that of particles having a particle size of 248-352μm is 10-60wt.%, and that of particles having a particle size of 352-800μm is 10-50wt.%.
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