| 摘要 |
PROBLEM TO BE SOLVED: To obtain an accurate apparatus for measuring a coefficient of linear expansion without being affected by the thermal expansion/thermal shrinkage of a base. SOLUTION: The apparatus comprises a laser light source 1, a temperature- controlling means 4, first and second beam splitters 9A, 9B, a reference CCR on the beam splitters 9A, 9B, targets CCRs 11A, 11B on a measurement axis while being separated from the reference CCR, light receivers 17A, 17B for detecting a change in interference fringes being generated by overlapping a first emission beam 15A that is reflected by the reference CCR 10A, 10B with second emission beams 15A, 15B that are reflected by target CCRs 11A, 11B, and displacement computing units 17A, 17B for calculating a change in the measurement axis distance between the reference CCRs 10A, 10B from signals from the light receivers 17A, 17B and the target CCRs 11A, 11B. COPYRIGHT: (C)2004,JPO
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