Apparatus for determining resonant frequencies of a specimen of magnetostrictive material
Abstract
Abstract NECTED IN A FEEDBACK ARRANGEMENT TO A SHIELDED DRIVE COIL SURROUNDING THE OTHER END OF THE SAMPLE. FREQUENCY FILTERING AND PHASE SHIFTING IN THE AMPLIFIER ASSURES OSCILLATION BY MAGNETOSTRICTIVE INDUCTION BETWEEN THE DRIVE COIL AND THE PICKUP COIL AT THE FUNDAMENTAL, LONGITUDINAL RESONANT FREQUENCY OF THE SPECIMEN. THE FREQUENCY IS MEASURED BY AN ELECTRONIC COUNTER. AN APPARATUS FOR THE ACCURATE DETERMINATION OF THE RESONANT FREQUENCY OF A CARBON SHEET STEEL SPECIMEN HAS A MEASURING HEAD OF THREE AXIALLY ALIGHED ENCIRCLING COILS SURROUNDING THE SPECIMEN. THE SPECIMEN MIDPOINT RESTING ON THE CENTER BIASING ENCIRCLING COIL PROVIDES THE SOLE SUPPORT OF THE SPECIMEN. A SHIELDED PICKUP COIL SURROUNDING ONE END OF THE SPECIMEN IS CONNECTED TO THE INPUT OF A HIGH GAIN AMPLIFIER, AND THE AMPLIFIER OUTPUT IS CON-
Inventors
- 👤 Thomas E Johnson Jr
- 👤 Peter R Mould
Bibliographic Details
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