PICA offers a wide range of handheld electromagnetic (EM) scanning tools to detect and measure wall loss in metallic pipes primarily used in our Intermediate NDT Service Solutions offering. We also can provide versions that are used to inspect the condition of reinforcing bars and prestressing wires in concrete pressure pipes.  Our low-frequency EM tools can be used on either the inside or the outside of the pipe.  The scan width is either 10 inches (external) or 24 inches (internal) at speeds of up to 3 fpm.  A magnetic wheeled robotic version and a version that inspects corrosion under insulation (CUI) are available.

PICA uses handheld ultrasonic thickness (UT) probes to quantify wall loss in metallic pipes.  Standard UT probes used by PICA on bare pipe can also be sold for purchase by the customer.  Electromagnetic acoustic transducer (EMAT) probes can measure wall thickness through a coating or insulation without the need for a couplant.

Bracelet Probe

Bracelet Probe 1 scaled
Bracelet Probe 2 scaled
PICA’s external Bracelet ProbeTM employs low frequency eddy current electromagnetic technology to produce a heat map of a scanned section of pipe where the different colors identify precise areas of localized wall loss, pits, or through-holes. Often, the locations of the scans are selected after a screening technology, such as free swimming leak and gas pocket detection is deployed or another inspection method, such as soil resistivity testing, indicates that there is a potential for either internal or external corrosion at the selected area.  Specialized Bracelet ProbeTM software produces wall thickness variation data in real-time, which allows the actual wall thickness to be quantified on-site while the pipe is still excavated using one of PICA’s hand-held UT probes.

The Bracelet ProbeTM also comes in a version that can be deployed on the inside of large-diameter pipe containing a steel cylinder to accurately measure wall loss at bends and other areas that are hard to reach with a large diameter RFT tool.


  • Produces a qualitative display of cylinder wall loss in cast iron pipe, ductile iron pipe, steel pipe (either coated or bare pipe), and concrete pressure pipes containing a steel cylinder (such as PCCP, bar-wrapped pipe, and reinforce concrete cylinder pipe).
  • Provides wire break measurements in embedded cylinder PCCP from the outside of the pipe; therefore, it is often used to validate NFT internal inspection results.
  • External inspection tool can be used to detect corrosion in the cylinder of bar-wrapped pipe through 2 inches or more of mortar coating.
  • External and internal versions of the tool are available.

    UT and EMAT Probes

    UT and EMAT Probes UT Probe 1 scaled

    Spot UT measurements are often used by PICA and our customers to accurately measure wall loss in metallic pipes at discrete locations.  This can include using a UT probe to validate wall loss data collected through our Remote Field Testing (RFT) or Bracelet ProbeTM inspections.

    UT works by transmitting a directional sound burst at regular intervals and waiting for an echo to be returned from a boundary of different material, such as air. The speed of sound is predictable; therefore, the interval between the transmitted and returned echo can be timed, allowing for the accurate measurement of thickness and position of flaws within the material being tested.

    If a spot UT thickness measurement is to be used, it must be considered that UT is very directional and will only measure the material directly under the transducer; it can miss a more severe thickness loss just a fraction of an inch away.

    Steel exhibits excellent acoustic properties and can support a high acoustic frequency with the advantage of providing a high-resolution UT measurement. Conversely, materials such as cast iron and ductile iron have a large grain structure, requiring a lower acoustic frequency, thereby offering a coarser measurement resolution.  For cast iron and ductile iron pipe, the Bracelet ProbeTM is often a better choice for wall loss measurements.


    • Can be used in conjunction with PICA’s Bracelet ProbeTM to quantify wall loss.
    • Can be used to validate wall loss data from PICA’s RFT tools.
    • Can measure wall loss through bare or coated/insulated pipe.
    • EMAT is better for use with cast iron pipe and ductile iron pipe.
    UT and EMAT Probes UT Probe 1 scaled
    UT and EMAT Probes EMAT Probe 2