How the MIT-SCAN-T3 works

The MIT-SCAN-T3 is used for both concrete thickness and asphalt thickness applications.

It uses Magnetic Imaging Tomography (MIT), a technique based on pulse induction technology which uses reflectors inserted into the pavement during construction.

The measuring results arise from an analysis of magnetic fields. Those so called answering fields are generated from eddy currents, which have been induced inside aluminium or zinc-plated steel reflectors as a reaction to a pulsed magnetic field. This Magnetic Imaging Tomography (MIT) measuring method is based on the principle of electro-magnetic tomography. Crucial innovations are the application of a sensor field and the analysis of the spatiotemporal answering signal.

The following reflectors are typical:

  • Asphalt– 7cm diameter Aluminium
  • Concrete – 30cm diameter Steel

The pulse induction technology leads to a high noise immunity and a wide measurement range. Probe head and electronic housing are connected through a take-apart central pipe.

A sensor field collects answering signals of metal reflectors. The analysis of the spatiotemporal gradient, which uses the methods of the electromagnetic tomography, avoids subjective measurement errors. A search mode allows for the very effective location of a reflector in a 2 m wide corridor, while the device is moved on a meander shaped path to 10 cm above the road surface. The presence of a reflector is shown as well on the display as through an acoustic signal. Immediately after the measurement, the results are displayed.