Inspection Methods – abbreviation cheat sheet

As an inspection and testing company we are often asked about what all the abbreviations mean in our industry. Terms that we use around here every day are confusing for others in the industry and realized that a cheat sheet was in order:

NDE  or NDT refers to Non Destructive Examination or Testing. (NDE is more common in the US)

Types of NDE or NDT include the following:

VT – Visual Inspection is exactly what it sounds like. It’s to look at something without the use of any additional equipment.

Bridge Fabrication

Next step of Bridge Fabrication

UT – ultrasonic flaw detection, or shear wave testing is similar to when you see that first ultrasound of your baby in the womb.  Just as the technician is looking for “defects” in the growing fetus, our technicians are looking for defects in the material or weld.


Phased Array

Phased Array

PMI – Positive Material Identification is equipment that tests for the chemical composition of a material.  Metal, or earth substances are all made up of chemical compositions.  Our analysts will tell you what percentage of each chemical is found in the material.

RT – Refers to gamma ray and x-ray testing is just like looking at a broken bone at the doctor’s office. Xray testing will look for “defect” in a weld. What’s really neat though is that this machine can be much stronger than what you get at the sport clinic. Our X-ray (gamma rays) can penetrate 3 inches of steel!

PT  or LPI  – Liquid penetrant testing, or Dye penetrant testing is a test that uses red dye working in 2 stages. First the material is prepared, then the dye is applied. If any surface cracks are present, the red dye will adhere to that area.

MT or MPI – Magnetic particle Testing, or Inspection makes use of equipment that uses an electro magnet to induce a magnetic field into the part that we are testing. The presence of discontinuity in the material allows the magnetic field ( Flux) to leak.  Ferrous iron particles are then applied to the part. If an area of flux leakage is present, the particles will be attracted to this area. The particles will build up at the area of leakage and form what is known as an discontinuity.

Magnetic Particle MT

Magnetic Particle Testing

This is what we do here at AXIS.   (along with a few other things, but we will save that for another blog)

Until next week.

Bonnie Pankratz