抄録
Nickelcopper alloy material is used as a part of electrode of an electronic tube.Before being assembled into electrode, the material is heattreated at 700° to 800°C in a hydrogen furnace to remove dirt and other substances from the surface and also to dehydrate and degas.By this heat.treatment, the material of certain lots gave trouble of its surface turning greyish-white in color.Application of simple statistical techniques to analysis lead to the discovery of the cause of discoloration being the presence of boron in the material, a good example of attempt in overcoming difficulties.The precision of detecting such lots by spectrochemical analysis is approximately 13% when expressed terms of coefficient of variation and 5% when there is no segregation in the boron content.
