(1) The principle of portable distinctness of image measurement is that a standard digital board is irradiated by a light source, and the light reflected by the quasi-digital board is reflected on the coated surface through two reflectors. The reflector is reflected to the visual mirror, and the observer observes the clarity of the series of images on the standard digital board through the visual mirror, and records the DOI value corresponding to the series that can be clearly read out.
(2) Image resolution method. Use the notched ring "LANDOL ring" to map on the surface of the tested coating film, and then evaluate the clarity of the image. It is a comprehensive reflection of specular luster, sharpness of reflection and haze that affect surface vision.
(3) The principle of the measuring instrument for coating tension is that at one end there is a built-in flash, frosted glass plate and grid line plate, and at the other end is an instant developing camera. Shoot the grid lines projected on the coating from the direction of reflection angle 60, and then judge the tension of the coating according to the clarity of the grid lines on the photo. This instrument can be used for the indirect evaluation of the orange peel of the coating.
(4) Determination of coating film visibility limit The measurement principle is that one side of the instrument is a scale, which is a series of hexagons from large to small with double lines inside, and there is an electronic flash above the scale. On the other side of the instrument is an instant camera that takes pictures at a 1:1 scale. During the measurement, the flashlight projects the graphics on the scale onto the surface of the coating film at an angle of 20°, and takes pictures in the direction of its reflection with a camera equipped with a white film. The limit to the sharpness of the graphics on the photograph is the limit to the visibility of the coating surface.
