Helium Light Band
A method of measuring seal face flatness. One helium light band equals 0.0000116 in. or 0.3 microns. Seal faces are normally lapped to within three helium light bands of flatness.
A method of measuring seal face flatness. One helium light band equals 0.0000116 in. or 0.3 microns. Seal faces are normally lapped to within three helium light bands of flatness.