| 摘要 |
PURPOSE:To determine accurate pitches by measuring the number of distance pulses in a test section and calculating the pitch at an arbitrary temp. CONSTITUTION:The entire part of a linear gage is maintained at the temp. at which a slit pitch assumes a known value, and a spindle 1 is moved by the length of the test section determined by photodetectors 7 and 9. The detection output produced as a slit plate 4 moves in the optical path for the light from light sources 6, 9 and entering photodetectors 7, 9 is fed to a control signal generating part 22. The switches 23, 24 at the output terminal thereof are held closed, and when the output of the photodetector 7 generates, a zero reset command is applied to a counter 21, and when the output of the photodetector 9 generates, a storage command is applied to a memory circuit 25, by which the number of the distance pulses generated in the test section is stored. The number of the distance pulses at an arbitrary temp. is likewise stored in the memory 25, and the change in the pitch between the distance pulses is determined by an operator 26 from the storage value of the coefft. of linear expansion between the slit plates 3, 4 and the test section whereby the accurate pitch is determined. |
