Comparison of performance of drop-sizing instruments

Area of Science:

• Fluid dynamics
• Metrology
• Aerosol science

Background:

• Accurate measurement of spray drop size is critical for various industrial and scientific applications.
• Variability in drop-size measurements can arise from instrument differences and spray characteristics.

Purpose of the Study:

• To evaluate and compare the performance of multiple drop-size measuring instruments.
• To identify systematic differences in instrument readings under standardized conditions.

Main Methods:

• Seventeen drop-size instruments of six types were tested using two standard spray types.
• Tests were conducted under well-defined conditions and measurement locations.
• Nominally identical atomizers were used across participating laboratories.

Main Results:

• Systematic differences in instrument performance were observed, exceeding variations from spray reproducibility.
• Differences in measured average drop size reached a factor of 5 between instruments.
• Good to excellent agreement was found between specific types of instruments.

Conclusions:

• Instrument selection significantly impacts spray drop-size measurement outcomes.
• Standardized testing protocols are essential for inter-laboratory comparisons.
• Further investigation into instrument-specific biases is warranted for improved accuracy.