Grease Spot Photometer
Comprises a waxed paper screen with a wax free central zone mounted on a black metal frame 100 x 75 mm, with a central aperture of 51 mm diameter mounted on rod.
Comprises a waxed paper screen with a wax free central zone mounted on a black metal frame 100 x 75 mm, with a central aperture of 51 mm diameter mounted on rod.