While spraying how do I know if I am applying at the recommended coverage rate e.g. 0.12 gallon/sq. yard?

The coverage rate dictates the film thickness which can be measured by a simple film thickness gauge, available at most paint stores. Select a 10’ x 10’ area of the pavement and place a 3"x 6" metal plate in the center. Spray sealcoating in this area and lift the metal plate before the sealcoating dries. Use the film thickness gauge to determine the wet film thickness. The reading will be in mils (1/1000 of an inch). Compare this reading with the desired film thickness for 0.12 gallon/ sq. yard coverage which is 21 mils.