System and method for measuring ultrasonic return signals
US4428237A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 13, 1980 |
| Grant date | Jan 31, 1984 |
| Priority date | — |
| Expiry date | Nov 13, 2000 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2291/2675
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An ultrasonic return signal analyzing instrument and method including analog circuitry for making partial power measurements on two selected frequency bands of the frequency spectrum of an ultrasonic return signal waveform and digital circuitry for measuring selected features of the envelope of the ultrasonic return signal waveform. Digital waveform measurements are converted to analog signals and then combined in an algorithmic combining circuit to produce a test statistic signal. A decision circuit receives the test statistic signal and registers a decision on a characteristic of the structure under examination based on the value of the test statistic signal. The instrument includes a signal normalization circuit to normalize the ultrasonic return signal to a fixed peak value and includes a frequency up-converter in the normalizing circuit and frequency down-converters in the partial power measurement circuits for increasing the accuracy of peak detection in the normalizing circuit and envelope detection for the partial power band signals and the total power signal. The digital waveform feature measurement circuitry includes circuitry for measuring the rise time and duration time…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.