Multi-band transducer for photoacoustic detection
OwnerS. Thomas Autrey, Gerald J. Posakony +2inventors
InventorsS. Thomas Autrey, Gerald J. Posakony, James E. Amonette, Nancy S. Foster-Mills
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Abstract
The present invention is a transducer for photoacoustic detection having at least two piezoelectric elements wherein at least a first piezoelectric element has a first frequency and at least a second piezoelectric element has a second frequency. The improvement according to the present invention is that at least two piezoelectric elements are longitudinal elements for longitudinal waves; and the first frequency is different from said second frequency. In other words, the invention is a multi-frequency longitudinal transducer for photoacoustic detection.
Claims9
A transducer for photoacoustic detection having at least two piezoelectric elements wherein at least a first piezoelectric element has a first frequency and at least a second piezoelectric element has a second frequency, wherein the improvement comprises:
- said at least two piezoelectric elements are longitudinal receiver elements for receiving longitudinal waves;
- and
- said first frequency is different from said second frequency.
In a mixture containing at least two chemical species, a method for identifying and measuring concentration of said at least two chemical species, comprising the steps of:
- passing pulsed excitation energy from a laser through said mixture thereby creating a photoacoustic signal;
- receiving said photoacoustic signal with at least two piezoelectric elements wherein at least a first piezoelectric element has a first frequency and at least a second piezoelectric element has a second frequency, wherein the improvement comprises:
- said at least two piezoelectric elements are longitudinal elements for longitudinal waves;
- and
- said first frequency is different from.said second frequency;
- and
- fitting four parameters with said first and second frequencies.
Dependencies are inferred from the claim text.