Specially by TQC developed instrument for use on wet lacquers, paint and coil coated surfaces. Equipped with a precision roller-bearing for smooth rolling over the surface . The wheel has three rims, the inner rim being eccentric to the two outer rims. The outer rings are notched for a firm grip inthe surface to prevent slipping. Made of stainless steel and with an aluminum grip.
Hold the wheel by its central spindle. Begin at maximum thickness to reduce risk of inaccuracy caused by surface tension.
Roll the wheel through the wet film with the side 1 in the diagram touching the substrate. Roll for at least one whole turn and slowly enough for wetting to occur. Roll the wheel backwards by at least on complete turn. The wet film thickness is read from the scale, at the end of the wetted segment of the middle circle, 2 in the diagram
To use wheel on pipes, measure across the longitudinal axis (lengthways) of the pipe.
On rough surfaces, measurements will be made from the surface peaks and represent the minimum wet film thickness.