QD12-07-C Flatness Of The Table Top Surface

The flatness check determines the distance 't' between two parallel planes within which the surface lies. The surface must be flat or concave.

Methods vary according to table size. Generally comparisons are made against a master straight edge, which is supported above the surface on, or close, to its minimum deflection points. Dial gauges or slip gauges are used for this purpose. A set of readings is taken across a diagonal, which would be repeated at a number of other diagonals.

A blue check with a master flat surface provides an immediate visual guide to the form.