Surface World December 2019 Surface World December 2019 | Page 46

TESTING & MEASUREMENT
working life. The
Ultra Scan probes
use the Elcometer
456’s patented
offset feature,
ensuring that the
thickness of the cap
is included in the
calibration
adjustment process
and discounted
from the thickness
readings. It should
be noted that the
ranges quoted
above are reduced
by the thickness of
the protective cap
which is
The Ultra/Scan Probe
with replaceable end caps
approximately 250
for increased durability
µm. As the cap
wears during use,
this effect on the
thickness readings is also taken into account. The gauge will display
a warning message when the degree of wear requires the cap
to be replaced.
The firmware for the Elcometer 456 Separate gauge, Top (T), has
been enhanced to allow the Ultra/Scan probe to be used and to
operate in either the Scan Mode or the Auto Repeat Mode. In Scan
Mode the probe can slide over the surface of the coating. As the
probe is lifted, the gauge displays the average coating thickness value
for the area, the highest thickness value and the lowest thickness
value. Each set of readings, generated when the probe is lifted, can
be displayed (average, high and low) on the run chart and stored in
the memory of the gauge.
In Auto Repeat Mode a reading is taken approximately every half
second as the probe slides across the surface, with each individual
reading stored in the memory of the gauge. With a reading rate in
excess of 140 readings per minute; the Auto Repeat Mode will
significantly speed up the testing of large areas of coating.
The Elcometer 456 Models S and T have the Counted Average
function as standard and this can be used to set the number of
readings in each area or spot and the gauge will then store the
average of these individual readings in the memory of the gauge.
The Fixed Batch Size feature on the Elcometer 456 T version allows
the maximum number of readings to be defined by the User for each
batch. Once this number of readings have been collected and stored,
the gauge automatically closes the batch and opens a new batch
linked to the previous batch, e.g. name-1, name-2, etc.
Specifications for coating thickness determination often describe the
number of individual thickness readings to be taken as a spot
measurement and the number of spot measurements for a given
area. For example, SSPC PA-2 requires three gauge readings per spot
and five spot readings in a 10 m² area.
With the Ultra/Scan Probe connected to the Elcometer 456 T version
with the Auto Repeat function selected, SSPC PA-2 (or similar test
specification) can be completed for a given area more than 40%
faster than with the more traditional measurement. A counted average
setting of three readings and a fixed batch size of five spot readings
The Elcometer 456 showing
the Run Chart display
The Ultra/Scan Probe in use
CONTINUED ON PAGE 46
44
DECEMBER 2019
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