초록 ▼

A non-contact, laser strain extensometer for use in materials testing utilizes a revolving laser beam to measure the separation of benchmarks placed on the specimen to be tested. The reflection of the laser beam from the benchmarks is focused on a photosensor to generate electronic pulses. The time

A non-contact, laser strain extensometer for use in materials testing utilizes a revolving laser beam to measure the separation of benchmarks placed on the specimen to be tested. The reflection of the laser beam from the benchmarks is focused on a photosensor to generate electronic pulses. The time duration between these pulses can be precisely measured using electronic counters. This time duration correlates with the distance separating the benchmarks. The revolving beam can be generated either by rotating polygonal mirror or an oscillating mirror.

대표청구항 ▼

In optical measurement apparatus for optically measuring deformation of a specimen under stress, the improvement comprising: A. marking means for marking the specimen with reflective benchmarks, B. scanning means for scanning an interrogating light beam across the specimen at a selected rate, so tha

In optical measurement apparatus for optically measuring deformation of a specimen under stress, the improvement comprising: A. marking means for marking the specimen with reflective benchmarks, B. scanning means for scanning an interrogating light beam across the specimen at a selected rate, so that light is reflected from said reflective benchmarks, C. photosensor means for receiving said light reflected from said benchmarks and for generating time-variant electronic pulses representative of said reflected light, D. time measurement means for measuring time between said pulses to provide a measure of separation between said benchmarks, and E. digital processor means, in electrical circuit with said scanning means, photosensor means, and time measurement means, for correcting geometric variances in measurement resulting from said scanning means.