Performing The Test; Assessing The Results (Destructive Testing) - Elcometer 508 Guia Del Usuario

6 PERFORMING THE TEST

1 Hold the gauge steady with one hand and
turn the crank handle clockwise slowly and
evenly to apply an increasing force to the
dolly and hence stress to the coating.
The rate at which the force is applied (the
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speed of rotation of the crank handle) should
be in accordance with the relevant Standard.
Continue until either;
(a) the coating fails and the dolly is
removed from the surface
(destructive testing) or;
(b) the minimum specified pressure value is
reached (non-destructive testing).
2 Record the pressure indicated on the display (a) and unwind the
crank handle and coarse adjustment screw.
DO NOT exceed the maximum pressure as overloading could damage the
gauge.
Note: Dollies can be reused after cleaning until either the top of the dolly is
severely deformed or the dolly surface is no longer flat, see Section 8.2
'Cleaning the Dolly' on page 7. Additional dollies are available from
Elcometer or your local supplier - see Section 10 'Spares & Accessories'
on page 9 for details.
7 ASSESSING THE RESULTS - DESTRUCTIVE TESTING
Once pulled from the surface, examine the bottom of the dolly to
assess the results.
a) Successful Test: In most cases the coating
will fully adhere to the dolly and the test can
be claimed as 100% valid.
b) Partial Failure: In some cases, the coating
will cover only part of the dolly face. A partial
adhesion / coating failure should be recorded
if the coating covers more than 50% of the
dolly face.
Cohesive Failure: When the coating fails in
the body of the coating layer leaving some
coating on the surface and some coating on
the dolly face.
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MAX
a)
b)
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a
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