描述了为外部浮顶储罐上使用的边缘密封确定蒸发边缘密封损失系数的程序。试验方法包括将受控的空气流速通过包含试验液体和试验轮辋密封件的试验室，并测量进出试验室的气流中试验液体蒸汽的浓度。本标准规定了要使用的试验装置、仪器、试验程序和计算程序。它还涉及要测量的变量、报告测试值的格式及其相关的不确定性。

Describes the procedures to establish evaporative rim-seal loss factors for rim seals used on external floating-roof tanks. The test method involves passing a controlled flow rate of air through a test chamber that contains a test liquid and a test rim seal, and measuring the concentration of the test liquid vapor in the air streams entering and leaving the test chamber. The standard specifies the test apparatus, instruments, test procedures, and calculation procedures to be used. It also addresses the variables to be measured, format for reporting the test values, and their associated uncertainty.