The effects of optical scattering on pulsed photoacoustic measurement in weakly absorbing liquids

• Published in: Measurement science & technology Vol. 12; no. 12; pp. 2172 - 2177
• Main Authors: Zhao, Zuomin, Myllylä, Risto
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 01.12.2001; Institute of Physics
• Subjects: Acoustic instruments, equipment, and techniques; Acoustical measurements and instrumentation; Acoustics; Exact sciences and technology; Fundamental areas of phenomenology (including applications); Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Metrology; Metrology, measurements and laboratory procedures; Optical instruments, equipment and techniques; Physics; Thermoacoustics, high temperature acoustics, photoacoustic effect; Ultrasonics, quantum acoustics, and physical effects of sound; Concentration measurement; Waveform analysis; Absorbing media; Diffusion coefficient; Optical scattering; Experimental study; Absorption coefficients; Optical absorption; Photoacoustic effect
• ISSN: 0957-0233; 1361-6501
• DOI: 10.1088/0957-0233/12/12/319

A photoacoustic technique, excited by a pulsed diode laser, is used in a study of optically absorbing and scattering liquids. Discusses the effects of optical scattering on the photoacoustic source and signal. In the empirical part, varying amounts of milk and carbon powder were added to water to control the absorption and scattering coefficients of the resulting liquids. The results showed that scattering increases the duration of the photoacoustic signal while decreasing the signal amplitude to some degree. Also shows a quite simple method for measuring the scattering coefficient in weakly absorbing materials using a PZT transducer. (Original abstract - amended)