Test results.
(1) Test results. You may use ASTM D269703 (R2014), Standard Test Method for Volume Nonvolatile Matter in Clear or Pigmented Coatings, or D609397 (R2016), Standard Test Method for Percent Volume Nonvolatile Matter in Clear or Pigmented Coatings Using a Helium Gas Pycnometer (both incorporated by reference, see 63.14), to determine the volume fraction of coating solids for each coating. Divide the nonvolatile volume percent obtained with the methods by 100 to calculate volume fraction of coating solids. Alternatively, you may use another test method once you obtain approval from the Administrator according to the requirements of 63.7(f).