Diesel fuel filter/water separators have become a popular product in the diesel engine industry. It is important to create laboratory test procedures that will permit the most effective analysis of what is happening to water in diesel fuel. Racor Industries, and Wally Stone and Steve Hardison, Racor research engineers, have developed a new technique for improving laboratory test procedures. It is a water dispersing technique that is designed to assure that water droplet sizes can be maintained within specifications that will permit the accurate analysis of filter/water separator water removal capabilities.