Remote three-dimensional temperature sensing using planar laser induced fluorescence : development and applications to microwave heated liquids

Microwave heating is an important technology that has been hampered in application by difficulties in measuring temperatures and temperature distributions during the microwave heating process. This thesis describes the development of a 3D imaging fluorescence thermometry system that was used to examine temporal and spatial variations in temperature within various aqueous solutions during their heating by microwave irradiation. The work provides one of the first experimentally-determined temperature maps for a system undergoing microwave heating. A 3D thermometry instrument was built based on the principles of Planar Laser Induced Fluorescence (PLIF) imaging. Temperatures were optically determined from ratiometric measurements of the fluorescence from a pair of molecular probes. A Dextran polymer labeled with Rhodamine B was used as a temperature-sensitive probe that operates between 20 and 60 ⁰C. A second temperature-insensitive probe, Rhodamine 110, was used to monitor changes in the laser emission intensity. A dual camera fluorescence detector system was employed to capture a 2D x-y plane at a specified z-axis position. A dichroic mirror and optical filters were used to separate the fluorescence signals from the two probes. The instrument was able to achieve a spatial resolution of 0.2 mm in x-y plane, a 5 mm spatial resolution in z-axis, and a temperature resolution of ±1.6 ⁰C. The 3D imaging thermometry instrument was modified for investigations into microwave heating. A microwave plasma applicator was adapted for heating experiments with water and salt solutions at concentrations ranging from 0-0.5 M.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Chemical Engineering.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2004

Author dc:creator

• Finegan, Timothy Michael

Advisor dc:contributor.advisor

• T. Alan Hatton and Paul E. Laibinis.

• Chemical Engineering.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

en_US

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/28356

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/28356