The picture shows an 8 channel U/T system that has just 4 primary adjusters.
This all means that life for the U/T operator can be easier if we accept that only
when wall thickness changes appreciably do we need a small relative adjustment between
transducer sets, and that 8 transducers can be set up with 4 adjusters, with a possible
minor pre-set adjustment if wall thickness is dramatically different.
For our international customers, here is a list of Canadian holidays and observances
for our offices for the next several months. Our automated answering machine can
take messages during evenings, weekends and holidays. Our offices will be closed
A few years ago, when much of the tube and pipe world was stampeding into phased
array technology, InspecTech decided to concentrate instead on developing discrete
arrays of conventional transducers to improve pipe testing performance but without
It turns out that our decision was sound as we continue across the industry, to replace
phased array systems that have lost their customer appeal; mostly for reasons of
excessive cost and complexity.
As our discrete arrays have developed, we have concentrated on maximizing user friendliness
and operational simplicity. With multi-probe assemblies, it is not smart to expect
the user to adjust 8 to 12 or more independent probes. This leads to awkward set
up procedures using complex test coupons. On the other hand, if too many functions
controlled by one or two controls only, the system loses its ability to deal with
a range of wall thickness conditions.
Take a look at the sketches above. A pair of closely matched transducers can cover
a wide area when properly spaced (sketch 1). Once the wall thickness increases however,
a gap can appear that will allow the same defect to slip through (sketch 2). A small
correction to one transducer (sketch 3), brings the system back to proper operation.
Vol.9 No.1, Spring 2014
DID YOU KNOW THAT?
All Inspectech tube testing equipment is designed and built to operate unattended.
Even our lowest cost eddy current units are configured to lift the test head clear
of danger zones such as windows and uncut od flash, and then return to full operation
once the hazard has passed. This feature means that operator intervention is needed
only during set up, and it minimizes the possibility of accidental damage to the
Recent versions of API specifications are clamping down on some types of testing.
Both API 5L and 5CT specify that if drilled holes are used as reference standards
for electromagnetic testing, then the user must demonstrate that an equal signal
can be obtained from an ID notch. This, of course, is very challenging indeed for
Eddy Current test systems, of which many hundreds are still in use in API mills.
The other available electromagnetic test system (flux leakage) will meet this API
requirement. The coiled tubing specification 5LCP still allows the use of drilled
holes making it the last API specification that could be termed “eddy current friendly.”