Measurement of dynamic modulus of

Claim 1

APPARATUS FOR MEASURING THE DYNAMIC MODULUS OF ELASTOMERS AND THE LIKE COMPRISING A VIBRATORY DRIVER, A TEST STANDARD OF A MATERIAL OF NEGLIGIBLE DAMPING, MEANS FOR COUPLING THE TEST STANDARD DIRECTLY TO THE DRIVER, A RESILIENT MEMBER COUPLED TO THE TEST STANDARD TO RESIST MOVEMENT OF THE TEST STANDARD BY THE DRIVER AND TO BE STRAINED IN PHASE WITH THE DEFLECTION OF THE TEST STANDARD, A RESISTANCE TYPE STRAIN GAGE ON THE MEMBER MEASURING THE STRAIN THEREIN CAUSED BY THE DEFLECTION OF THE TEST STANDARD, ANOTHER RESILIENT MEMBER EQUIPPED WITH ANOTHER RESISTANCE TYPE STRAIN GAGE FOR MEASURING THE STRAIN THEREIN, A TEST SPECIMEN ARRANGED BETWEEN SAID OTHER MEMBER AND THE DRIVER SO AS TO STRAIN SAID OTHER MEMBER WITH A COMPONENT OF STRAIN IN PHASE WITH THE DRIVER PROPORTIONAL TO THE ELASTIC MODULUS OF THE TEST SPECIMEN AND WITH A COMPONENT OF STRAIN OUT OF PHASE WITH THE DRIVER PROPORTIONAL TO THE DAMPING MODULUS OF THE TEST SPECIMEN, AND A STRAIN MEASURING CIRCUIT FOR BALANCING OUT THE IN PHASE RESISTANCE OF THE STRAIN GAGES WHEREBY THE INDICATION OF SAID MEASURING CIRCUIT IS THAT DUE TO THE OUT OF PHASE STRAIN COMPONENTS PROPORTIONAL TO THE DAMPING MODULUS OF THE TEST SPECIMEN.