TECHNOVOTUM - development and production of equipment and technologies for non-destructive testing (NDT)

Tomographic 1.2 – EMA Thickness Meter


 

"Tomographic 1.2" implements simultaneously functionalities of both EMA (electromagnetic acoustic) and ultrasonic precision thickness meter. Advantages of the contactless EMA method are based on its physical properties, which makes it possible to test objects without coupling media, as well as to work with materials having contaminated surface (rust, corrosion, etc.) and paint-and-lacquer coatings. Stable operation of EMA probe (EMAP) is ensured at air gap with tested surface within (0...1.5 mm) depending on conductivity of the tested material.

For thickness measurement, probes of several types are used:

  • EMAP – single probe
  • EMAP – dual probe
  • PEP – single probe
  • PEP – dual probe

In EMA thickness meter, three methods of signal processing are used: resonance, correlation and pulse.

For every method, calibration by means of reference blocks (by thickness or USW propagation velocity in the block).

Measurements under resonance method are used for especially thin articles, where high accuracy class is required:

  • 0.2 mm to 1 mm (PEP)
  • 0.3 mm to 0.7 mm (EMAP)

Measurements under correlation method are performed when there are at least two bottom echo-signals (error decreases with increase of the number of echo-signals). Application of this method is designed for operation within middle ranges:

  • 1 mm to 60 mm (PEP)
  • 0.7 mm to 60 mm (EMAP)

Measurements under pulse method are performed using single bottom signal and are used for estimative determination of thickness within following ranges:

  • 10 mm to 4,800 mm (PEP)
  • 5 mm to 650 mm (EMAP)

Software is provided with new functional possibilities to facilitate considerably the operator’s work and to accelerate the testing process:

  • Automatic determination of contact between probe (PEP or EMAP) and tested surface, as well as possibility to enable/disable this function;
  • In correlation and pulse methods, semi-automatic (manual fine tuning) and automatic adjustment is provided, which makes it possible to commence with object testing without presetting of instrument. In pulse method, among others, the function of automatic positioning of 1st echo-pulse is implemented. This functionality also can be enabled or disabled;
  • А-scan + В-scan allow deviations from permissible thickness to be traced quite conveniently; unacceptable deviations are indicated by instrument using indicator of the automatic flaw signaling unit (monitor);
  • Automatic gain control excludes the need in continuous setting of required value when the tested object is changed; for convenience of use, manual adjustment is kept as well;
  • In addition to the tabular presentation of results, thickness map is implemented, which makes it possible to evaluate the tested object in whole with its graphical presentation reflecting visually areas of unacceptable thickness deviations;
  • Archive of settings with volume for 1,000 records allows any required setting to be saved and downloaded
  • Archive of test results makes it possible to save, as well as to download any required record, to review it on the instrument screen and to prepare the test report.
  • Test results are documented by means of universal application NDT operator AWS.