Photoelastic stress sensor signal processor
US4515473A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 13, 1984 |
| Grant date | May 7, 1985 |
| Priority date | — |
| Expiry date | Sep 13, 2004 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B11/18
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A signal processor is arranged to process polarized light signals obtained from a stress sensor of the type having a photoelastic element that responds to stress by causing a phase difference between components of the polarized light propagating through that element. The stress sensor provides two output beams, each of which has a different polarized component of the transmitted light. The signal processor employs a pair of photodetectors which respond to the intensities of the two polarized light beams by converting the polarized light into electrical signals. Those two electrical signals provide the inputs to a difference differentiator that provides an output proportional to the difference between the derivatives of the inputs. The two electrical output signals of the photodetectors are also applied as inputs to a multiplier whose output is related to the product of its inputs. The square root of the output of the multiplier is obtained from a square root device and is used as the divisor in a divider whose numerator is the output of the difference differentiator. The output of the divider is applied to the input of an integrator whose output is a measure of the stress imposed o…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.