Constant-frequency pulsed phase-locked-loop measuring device is sensitive to small changes in phase velocity and easily automated. Based on use of fixed-frequency oscillator in measuring small changes in ultrasonic phase velocity when sample exposed to such changes in environment as changes in pressure and temperature. Automatically balances electrical phase shifts against acoustical phase shifts to obtain accurate measurements of acoustical phase shifts.
Constant-Frequency Pulsed Phase-Locked-Loop Measuring Device
NASA Tech Briefs ; 17 , 4
1992-04-01
Miscellaneous
No indication
English
Pulsed Phase-Locked-Loop Strain Monitor
NTRS | 1982
|Double-Referenced, Pulsed, Phase-Locked Loop - DRP2L2
NTRS | 1987
|NTRS | 1967
|