AAAR 33rd Annual Conference
October 20 - October 24, 2014
Rosen Shingle Creek
Orlando, Florida, USA
Abstract View
A Novel Instrument for Measuring Broadband Optical Properties of PM Deposited on Filters
KEITH BEIN, Charles McDade, UC Davis
Abstract Number: 487 Working Group: Instrumentation and Methods
Abstract A new instrument called BITS (Broadband Integrating Transmittance/Reflectance Spectrophotometer) has been designed and constructed to allow light absorption and fluorescence measurements to be made using broadband radiation spanning the ultraviolet to near-infrared spectral range. The broadband light source has an output spanning 190 to 1700 nm, which is accomplished by the combination of a deuterium and tungsten halogen lamp. Light from the source is directed through a collimating, filtering and focusing assembly and then onto the PM deposit. An integrating sphere captures light reflected, or back emitted, from the deposit, and both the reflected light and the light transmitted through the deposit, or forward emitted, are measured by a single CCD detector via novel collection optics assemblies and a custom bifurcated fiber optics bundle. Absorbance is determined from the reflected and transmitted measurements. Fluorescence is measured by filtering the visible and near IR radiation from the incident light beam and using the CCD detector to measure any emitted visible radiation. Theoretical considerations and the design of BITS, as well as calibration procedures and first results from measurements on filters collected by the IMPROVE network, will be presented.