title: Photoacoustic measurement of the Grüneisen parameter using an integrating sphere.
abstract: A method that uses an integrating sphere as a platform for photoacoustic measurement of the Grüneisen parameter Γ of absorbing liquids is developed. Derivation of a simple equation for determining Γ is presented. This equation only requires the voltage peak-to-peak value of the photoacoustic signal detected by a flat transducer and the relative energy of the incident light measured by a photodetector. Absolute detector sensitivities are not required. However, a calibration procedure is necessary. An experimental setup is constructed in order to implement and verify the method. Aqueous ink solutions are used as absorbing liquids to determine the calibration (instrument) constants. Validation of the equation is done by determining Γ of ethanol at room temperature. The obtained value of Γ(ethanol) = 0.72 ± 0.06 has a 7% relative difference to the calculated value from known thermal properties reported in literature.
authors.affiliation: BioMedical Photonic Imaging Group, MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands.
authors.forename: Yolanda
authors.initials: Y
authors.lastname: Villanueva
authors.affiliation: BioMedical Photonic Imaging Group, MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands.
authors.forename: Erwin
authors.initials: E
authors.lastname: Hondebrink
authors.affiliation: BioMedical Photonic Imaging Group, MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands.
authors.forename: Wilma
authors.initials: W
authors.lastname: Petersen
authors.affiliation: BioMedical Photonic Imaging Group, MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands.
authors.forename: Wiendelt
authors.initials: W
authors.lastname: Steenbergen
mesh_terms: D002138:Calibration; D004867:Equipment Design; D000431:Ethanol; D007281:Ink; D008027:Light; D008962:Models, Theoretical; D061088:Photoacoustic Techniques / Q000295:instrumentation*; D012996:Solutions; D013696:Temperature
chemical_list: D012996:Solutions; D000431:Ethanol