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Pseudo continuous wave instrument. [ultrasonics
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Copyright Year | 1978 |
| Description | Acoustic properties and their changes in a sample of liquid, gas, plasma or solid are measured by applying a variable frequency source to the sample by means of a transducer to produce sound waves within the sample. The application of the variable frequency source to the sample is periodically interrupted for a short duration. Means are connected to the transducer for receiving the resulting acoustic signals during the interruptions for producing a control signal indicative of a difference in the frequency of the output of the variable frequency source and the frequency of a mechanical resonant peak in the sample. The control signal is applied to the variable frequency source to maintain its output frequency at the frequency of the mechanical resonant peak. The change in frequency of the variable frequency source indicates the shift in frequency of the mechanical resonant peak and the amplitude of the acoustic signals indicates the attenuation of the acoustic signals in the sample. |
| File Size | 428170 |
| Page Count | 6 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19790002219 |
| Archival Resource Key | ark:/13960/t77t2h36c |
| Language | English |
| Publisher Date | 1978-10-03 |
| Access Restriction | Open |
| Subject Keyword | Frequency Modulation Acoustic Measurement Acoustic Properties Phase Shift Sound Transducers Signal Detectors Continuous Radiation Oscillators Ultrasonics Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Patent |
