This standard specifies the method for determining the deposition efficiency during the electrostatic spraying of powder coatings. The principle involves using an electrostatic spray gun to apply powder onto a specially designed target tube under standard conditions, precisely weighing the mass of the powder deposited on the target tube, and calculating the deposition efficiency as the percentage of this mass relative to the total mass of the sprayed powder. This method is applicable to powders charged by corona or triboelectric means, and can be used for horizontal comparison of the efficiency of different powders with the same spray gun, or for evaluating the performance of the same powder with different spray guns. It should be noted that this method is primarily intended for continuous comparison, and its results can be significantly affected by variations in environmental conditions and equipment over time and location.