Absolute light scattering photometer

The Brice-Phoenix light scattering photometer and the Absolute light scattering photometer were designed for the measurement of attenuation, dissymetry and depolarization. The former has also been used to determine the particle size distribution of an aerosol at various levels in a flowstream through a column [125]. 

Light scattering photometer, with absolute calibration carried out in advance plus appropriate neutral filters, and data collection system... 

The absolute calibration of light-scattering photometers has received more attention recently, and critical reviews of the technique and standard values have appeared. 

Light-scattering Photometer OM-2000 Brice-Phoenix Absolute values via Zimm plots... 

The instrument used in the author s laboratory is an absolute photometer with chopper and lock-in amplifier, yielding absolute Rayleigh ratios (9)- Photographic recording of light scattering patterns which has proven to be of value for the characterization of crystalline polymer films usually fails for networks - whether dry or swollen - because of the much lower levels of scattering. 

Calibration is required to convert measurements of scattered light intensity from arbitrary to absolute values, an essential step in the calculation of molecular weight. Fortunately, because the calibration constant of most photometers remains stable for long periods of time, the calibration procedure need be carried out only infrequently. Should it need to be calibrated, the procedure described in ASTM D4001-93 or that of the instrument vendor should be followed. 

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