| 摘要 |
The present invention non-destructively measures the strain distribution of entire quartz glass crucibles. A strain measurement device which comprises: light sources (11) which irradiate a quartz glass crucible (1) with light from the outside thereof; first polarising plates (12) and first quarter wavelength plates (13) which are disposed between the light sources (11) and the outer surface of the wall of the quartz glass crucible (1); a camera (14) which is disposed inside the quartz glass crucible (1); a camera control mechanism (15) which controls the direction of imaging of the camera (14); and a second polarising plate (16) and a second quarter wavelength plate (17) which are disposed between the camera (14) and the inner surface of the wall of the quartz glass crucible (1). The optical axis of the second quarter wavelength plate (17) is inclined by 90° relative to the optical axis of the first quarter wavelength plates (13). The camera (14) is irradiated with light from the light sources (11) and images the light which has passed through the first polarising plates (12), the first quarter wavelength plates (13), the wall of the quartz glass crucible (1), the second quarter wavelength plate (17), and the second polarising plate (16). |
