Method and apparatus for monitoring cracking using stress wave emission techniques
US4207771A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 2, 1979 |
| Grant date | Jun 17, 1980 |
| Priority date | — |
| Expiry date | Mar 2, 1999 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S7/527
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The disclosure is directed to a technique for monitoring signals emanating from a ceramic article (10) during a soldering operation. In order to determine whether the signals are stress wave emissions (SWE's) or noise the number of pulses (41) of the monitored signal having an amplitude exceeding a preset threshold (51), during a period of time, are counted. A count (62) proportional to the area under the envelope of the detected signal during the period of time is also made. A ratio of the count related to the area under the envelope to the pulse count is formed and compared to an empirically developed range of ratios which are indicative of a stress wave emission signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.