Total Distance (TotDist)

In our MX 203 Series Contactless Wafer Geometry Gauges, the evaluation of all
wafer geometry characteristics is based upon distance measurements performed by
multiple capacitive sensors embedded in two probe plates facing each other, and the
surface of the test piece positioned in the air gap between the two plates. Thanks to
correction data yielded by the calibration procedure, the two probe plates can be
assumed to be perfectly flat, and to be mounted in a constant total distance between
each other.

\(\text { AvgThk }=\frac{\sum T h k(i)}{n}\)