Abstract

Standard rainbow thermometry connects the scattering angle of the main rainbow maximum, generated by a single droplet, to the droplet’s refractive index and thus to its temperature. Droplet nonsphericity influences the rainbow position and therefore degrades the quality of the droplet-temperature measurement. We propose global rainbow thermometry, which measures the average rainbow position that is created by multiple droplets and from which a mean temperature can be derived. The new technique aims at eliminating the nonsphericity effect. The principle of this method is presented, and a typical recorded image is discussed.

© 1999 Optical Society of America

Global rainbow thermometry assessed by Airy and Lorenz-Mie theories and compared with phase Doppler anemometry

Jeronimus Petrus Antonius Johannes van Beeck, Thomas Grosges, and Maria Grazia De Giorgi
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Composition measurements of binary mixture droplets by rainbow refractometry

J. Wilms and B. Weigand
Appl. Opt. 46(11) 2109-2118 (2007)

Rainbow refractometry: simultaneous measurement of temperature, refractive index, and size of droplets

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Rainbow phenomena applied to the measurement of droplet size and velocity and to the detection of nonsphericity

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Global rainbow thermometry: improvements in the data inversion algorithm and validation technique in liquid-liquid suspension

Maria Rosaria Vetrano, Jeronimus Petrus Antonius Johannes van Beeck, and Michel Léon Riethmuller
Appl. Opt. 43(18) 3600-3607 (2004)