Comparison of Drop-Size Measurements for Similar Atomizers

The performance of 17 drop-size measuring instruments including six different types were compared for two types of standard sprays. Ten instruments were compared on one type of spray, and eleven on the other, with some instruments used on both types. A number of nominally identical atomizers were tested at different 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 five. However, good to excellent agreement was observed between observations for some types of instruments. Keywords: Atomization; Drop size measurements; Drops; Measuring instruments.