Telephone: 01202 530166 | 07795 903858

Specialist NDT Testing Methods - Part 1

Magnetic Particle Inspection

Magnetic Particle Inspection (MPI) is used to detect cracks, stress fractures and other non-visual defects on ferromagnetic materials. This widely used method can be applied to various areas of a street lighting column or high mast but in particular around the corners of a column door or at welds such as the shaft or bracket assembly and where access is available on one surface only.

This test method begins with white paint being applied to the surface being inspected. A solution containing very fine iron particles is then applied and the area is magnetised using either a permanent or electro-magnetic current. If a defect is present the magnetic flux leaks through the defect attracting the iron particles and forms a visible line.

On completion, a detailed report is drawn together outlining the areas inspected and the general findings. If a defect has been noted then the report will give details of the exact location, nature of the defect and possible recommendations for remedial action.

Ultrasonic Thickness Testing

By testing two sections of a street lighting column – the column base (above ground) and the column shaft (swaged/welded section), using a multi-echo ultrasonic thickness gauge we are able to determine the remaining metal thickness and highlight dangerously corroded areas.

Flooded Member Detection

Flooded member detection is used to determine whether a defect within the column has allowed the ingress of water. The presence of water is a major contributor to corrosive activity. Using specialised ultrasonic equipment, which is first calibrated to the type of metal being inspected, a series of readings are taken at various points on the column base. By increasing and decreasing the height of the inspection, it is possible to determine the level to which water has risen.

About Intratest
As part of our commitment to raising standards within our industry, we continually develop the management of our day-to-day activities, through our Business Management Systems, that are independently verified through 3rd party audits to meet industry standards and best practice.

Giving you the reassurance that we operate to the highest possible standards always.

If you have any questions, or need clarity on what is said on our website, please pick up the phone, or click below to send an email, to get the answers you need.


Continually push the boundaries to provide professional, cost effective solutions for our customers in a straight forward, no-nonsense and honest manner.

An approach that is complimented by our commitment to continue to engage, educate and mentor asset owners to ensure that integrity-based solutions become the norm.


  • Proactive Asset Management Programmes
  • Complete NDT Services
  • Integrated solutions
  • Added value & cost effective
  • Market leading technology
  • Conformity to GN22
  • Pinpoint exact seat of corrosion
  • Failures reported immediately
  • Engineers located across the UK

Maintaining Standards

Intratest has joint UKAS certification to ISO9001:2015 and NHSS8 within the Street Lighting Industry.