"Global experts for local problems such as Heat Treating, Quenching, Thermal Processes, Fluids, Lubricant, Consulting & Research Service."
P.O. Box 55518
Seattle, WA 98155 U.S.A.
Tel: +1 (206) 788-0188
Fax: +1 (815) 461-7344
Home > Testing Equipment > Grindosonic
Measure Resonant Frequency Accurately in Seconds. Use to Calculate Modulus. Correlate Variations in Frequency or Modulus with Other Variables e.g., mechanical properties, microstructure, composition.
How Does It Work?
It "listens" to the vibrations resulting from a simple tap. filters out the noise and harmonics, and displays the fundamental resonant frequency. The tapper may be a plastic bead on a stick or a screwdriver handle. For "listening", a supersensitive piezo-electric (contact) probe is furnished. An alternate device (optional) is a (non-contacting) microphone with equivalent sensitivity.
Modulus is calculated by the optional computer program after input of frequency, dimensions, and weight. If the torsional frequency is entered along with that of either the flexural or the longitudinal mode of vibration, the program will determine the values of modulus of elasticity (E), modulus of rigidity (G), and Poisson's Ratio (PR).
What Is It Good For?
Obviously, to determine E, G, & PR for design and stress analysis purpose, unconstrained by specimen size limits or hostile environments. Other applications range from process control through design and development to exotic research. Use of the correlations is valid, even when frequency differences are very smal, due to the phenomenal precision or the GrindoSonic readings.
It call be used on all rigid materials: metals, ceamics, glass, refractories, cement, concrete, composites, graphite, plastics, wood, rock. Samples range from tiny bars with square or circular cross sections to quarter-dollar size discs to 20 goot long beams.
The Grindo-Sonic exhibits phenomenal sensitivity and extraordinary precision (the scatter of multiple readings approximates ±0.01%). This latter characteristic ensures the validity of small frequency differences found among like samples having defects or identical microstructures, e.g., 17-4PH stainless (or alloy) steel bars aged (or tempered) at 1000°F & 1050°F. As an example of sensitivity the presence of a 0.05 µm zirconia coating on 0.035" thick titanium was recently detected.
The test is not constrained by hostile environments (e.g., 2000°F) or sample size limits; it could be as small as your fingernail or as large as your car. The results can be used to calculate E, G, & PR which often correlate with other properties. However, if the shape is complex, you can compare moduli of apparently identical samples by comparing the squares of their resonant frequencies. (Note particularly, graph titled "INADEQUATE SOLUTION HEAT TREATMENT".)
Free testing of samples and contract testing of parts/specimens at room and elevated temperature is avaiable. The GrindoSonic instrument is supplied by conventional sale and lease/option.[View Application Examples]
Copyright © 2003
Web site designed by DHx2 Media for G.E. Totten & Associates, LLC
Legal Notice: All contents on this site is copy righted and belongs to Dr. George E. Totten. Distribution, transmission or republication of any material from this site is strictly prohibited without the prior written permission of Dr. George E. Totten. For information please contact us or email the webmaster.