18 ElektroPhysik
enough not to give way under the pressure of the
probe tip. A thin layer of aluminium foil can be
suitable, if stuck on a hard base.
The enclosed steel and aluminium zero plates are
for test purposes only and are generally not
recommended for calibration.
Exceptions:
The zero plates may be used for calibration if the
product sample has a smooth, even surface (not
shot-blasted) and
-
if steel parts are thicker than 1 mm (40 mils).
In this case, the zero plate may be used for
calibration by laying it on the coated sample.
-
if aluminium parts are thicker than 50 µm
(2 mils). In this case the enclosed aluminium
plate may be used for calibration. (Thin layers
of aluminium foil should be stuck to a hard
base.)
Effects of substrate thickness
