Ultrasonic transducer and gas analyzer

Claim 1

APPARATUS FOR COMPARING AN UNKNOWN GAS WITH A GAS HAVING KNOWN PROPERTIES, INCLUDING IN COMBINATION, MEANS FORMING A CHAMBER, TRANSDUCER MEANS COMPRISING AN ELONGATED BODY HAVING FIRST AND SECOND ENDS AND HAVING DIMENSIONS TO BE RESONANT IN LONGITUDINAL VIBRATION AT A PREDETERMINED OUTPUT FREQUENCY AND FURTHER HAVING A NODAL PLANE OF VIBRATION, SAID TRANSDUCER MEANS FURTHER INCLUDING A PIEZOELECTRIC DRIVING MEMBER PLACED IN SAID CHAMBER TO FORM FIRST AND SECOND CONTIGUOUS SUBCHAMBERS OF SELECTED DIMENSIONS, SAID FIRST SUBCHAMBER ADAPTED FOR CONTAINING SAID GAS OF KNOWN PROPERTIES AND SAID SECOND SUBCHAMBER ADAPTED FOR CONTAINING SAID UNKNOWN GAS, SAID PIEZOELECTRIC DRIVING MEMBER ENGAGING THE NODAL PLANE OF SAID BODY TRANSVERSE TO THE AXIS OF LONGITUDINAL VIBRATION SO THAT THE FIRST AND SECOND ENDS OF SAID BODY EXTEND RESPECTIVELY INTO SAID FIRST AND SECOND SUBCHAMBERS SAID TRANSDUCER MEANS FURTHER INCLUDING ELECTRODE MEANS ON SAID PIEZOELECTRIC DRIVING MEMBER ADAPTED TO APPLY AN ALTERNATING CURRENT VOLTAGE OF A GIVEN FREQUENCY THEREACROSS FOR STRAINING SAID DRIVING MEMBER, FIRST AND SECOND SENSING MEANS IN SAID FIRST AND SECOND SUBCHAMBERS RESPECTIVELY AT GIVEN DISTANCES FROM SAID FIRST AND SECOND ENDS OF SAID BODY, EACH OF SAID SENSING MEANS PRODUCING AN ALTERNATING CURRENT VOLTAGE SIGNAL OF A FREQUENCY CORRESPONDING TO THE SIGNAL SAID SENSING MEANS RECEIVES FROM SAID TRANSDUCER, AND PHASE DETECTOR MEANS COMPARING THE PHASE OF SAID ALTERNATING CURRENT VOLTAGE SIGNALS FROM SAID FIRST AND SECOND SENSING MEANS AND PROVIDING AN INDICATION OF THE VARIANCE THEREBETWEEN.