PRECISION ULTRASONIC MEASUREMENTS FOR MICROBUBBLE RESEARCH,
Abstract
New techniques are described for the measurement of ultrasonic attenuation and velocity in water at three frequencies in the 1-10 megacycle range. The basic instrument configuration is that of a Mach-Zehnder type intmeter, with one path including the ultrasonic cell and the others, a precision attenuator. The cell consists of three frequency transducer, a supporting cage, and a reflector, with a folded, one meter path length. In operation, the signal source is switched for a short pulse interval to the ultrasonic cell, and then returned to the attenuator path. This pulse, delayed by transit through the cell, is mixed with the attenuator signal to obtain a null and displayed on an oscilloscope. Ultra sonic attenuation is determined from the attenua tor setting, and ultrasonic velocity from the frequency interval between nulls. Standar devia tion of relative attenuation measurements is 0.12 db, and of relative velocity measurements, three parts in 100,000. The certainty of indivi dual relative velocity measurements, however, is one part in 10,000. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 26, 1963
- Accession Number
- AD0413052
Entities
People
- W.r. Turner