ABSTRACT
The performance of seventeen drop-size measuring instruments including six different types were compared for two types of standard spray. Ten instruments were compared on one type of spray, and eleven on the other, with some instruments being used on both types. A number of nominally identical atomizers were made available for testing at laboratories using drop-sizing instrumentation. These tests followed a set of well-defined test conditions and measurement locations as defined by a committee of test participants. The results indicated systematic differences in instrument performance beyond what could be attributed to problems in spray reproducibility. Differences in average drop size were as large as a factor of 5. However, good to excellent agreement was observed between observations for some types of instrument.
ABSTRACT
The purpose of this paper is to compare the drop sizing results of an Aerometrics phase/Doppler particle analyzer with those of a Malvern laser-diffraction instrument. Measurements were performed on a small pressure-swirl atomizer. Since the laser-diffraction instrument measures a line-of-sight average through different regions of the spray while the phase/Doppler instrument characterizes the spray in a small volume, a conversion procedure was necessary prior to comparison. After conversion to equivalent forms, the point-measured average drop sizes exhibited similar trends throughout the spray, but the phase/Doppler values were generally larger. The total volume flow rate measured by the phase/Doppler instrument was inconsistent at different axial locations but significantly larger than the actual value at most locations.
ABSTRACT
NO(2) absorption coefficients for the most prominent argon-ion laser lines have been measured. A technique for measurement of NO(2) concentration in an urban atmosphere in real time is described. Preliminary results using the differential absorption of argon-ion laser lines by NO(2) in an urban (Atlanta, Georgia) atmosphere are presented. A simplified detection system using the differential absorption is proposed.
