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34 Wire & Cable ASIA – March/April 2013
Expanding its non-destructive testing
(NDT) techniques and complementing
its existing array of advanced
instruments, Keighley Laboratories has
invested in a portable conductivity
meter and a pocket measuring
instrument.
The meter measures the electrical
conductivity of non-ferrous metals
employing the eddy current method,
and the pocket instrument is used for
convenient and fast coating thickness
measurement, using magnetic ind-
uction and eddy current technologies.
Both measuring techniques are
applicable to the aerospace,
automotive, petrochemical, engin-
eering, heat treatment and other fields
and complement the specialist NDT
services Keighley Laboratories already
offers to industry clients.
Through its technical services division,
Keighley Labs covers many of the
mainstream NDT methods, notably
magnetic particle crack detection, dye
penetrant testing, ultrasonic flaw
detection, magnetic permeability,
positive material identification, residual
magnetism and ferrite determination,
as well as radiography on a
sub-contract basis.
Its NDT technicians are qualified to at
least PCN Level 2 in several disciplines
and are able to define and implement
tests that detect and analyse material
flaws that might otherwise give rise to
critical component failure or quality
control issues, either working in the
laboratory or at the customer site.
Many methods are covered by the
company’s UKAS accreditation, for
testing at customer premises.
The electrical conductivity of a metal
depends on various factors, such as
chemical composition, the stress
state of its microstructure and
mechanical properties, so can be
used for sorting metals and checking
proper heat treatment, as well as
identifying how well a metal conducts
electrical current for anodising and
other processes.
The company’s new instrument will
measure the electrical conductivity of
non-ferrous metals, such as aluminium
alloys, copper and even stainless
steels, using the eddy current method
in accordance with DIN EN 2004-1 and
ASTM E 1004 standards and
determining conductivity of materials
under paint or synthetic coatings up to
500µm thick.
Employed both in-house and for
external clients, it will enable the
company to monitor the hardness and
strength of heat treated materials like
aluminium alloys and inspect for any
heat damage.
The same instrument will also be used
for scrap metal sorting at customer
sites, determining the purity of
non-ferrous metals and verifying the
homogeneity of alloys, as well as for
the inspection of finished goods. It will
even detect counterfeit coins.
The other NDT technique, for
measuring the precise thickness of
such applied coatings as paint,
powder coatings, plastics and plated
finishes, is equally important for
ensuring compliance with thickness
specifications, preventing defective
coatings and subsequent corrosion,
maintaining product quality and
controlling production costs.
The company’s newly-acquired pocket
instrument will provide for
non-destructive measurement of the
total thickness of coatings up to
2,000µm thick, applied to ferrous and
non-ferrous materials.
It will automatically recognise the
underlying material, such as steel or
aluminium, and select the appropriate
one of two test methods, which are
eddy current and magnetic induction in
accordance with ISO 2178, ASTM
D7091 and ISO 2300 standards.
With an on-board memory for up to
1,000 readings, it will allow Keighley
technicians to measure paint, lacquer
or plastic coatings on a whole range
of metals, anodised coatings on
aluminium components, electro-
plated zinc, chromium and copper
finishes, and sputtered thin-film
deposition.
As with all advanced NDT techniques,
a considerable degree of operator skill
and experience is required to apply
these test methods properly, obtain the
maximum amount of information, then
interpret the results and provide
feedback for the client.
Keighley Laboratories – UK
Website:
Two new portable non-destructive
testing instruments from Keighley