Pinning down unreliability enables the degree of precision to be maintained

When we asked Mr. Sasaki what the most difficult part of the craft of machine inspection is, he replied that it is "pinning down unreliability."

No matter how accurately one carries out measurements, discrepancies and variations from the true values will always creep in. There are various factors involved in the occurrence of these variations. Pinning down unreliability entails understanding these factors and estimating the degree of variation in the measurement values.

As Mr. Sasaki says, "Even a 0.1°C change in room temperature will probably affect the results of measurement. Different people may also obtain different results when they carry out measurements. On the other hand, there are also factors whose effect on measurements need not be taken into account. The process of pinning down which factors affect the measurement values and to what degree they do so, and then minimizing the variations, is one of the more difficult aspects of machine inspection."

Mr. Sasaki's work is not directly involved with manufacturing. Instead, he fulfills a vital supporting role behind the scenes that contributes to the precision of Nikon products. Despite frequent company re-organizations, the Measurement Section to which Mr. Sasaki belongs has retained the same office name for more than 50 years. This is testimony to the fact that over the course of many years Nikon has placed a premium on the craft of machine inspection.