There are times when we need to have a little information about a piece or some type of material, for example, the thickness of it, without the need to make any cut of that material, for which Ultrasound created the Thickness Gauge.
These devices are not new, since they were created in the 1960s, as a derivation of sonar, and from those days until the recent era, they have evolved significantly.
The principles of ultrasonic thickness measurement
- Use of separate transmit/receive translators, allowing a “pseudo-focusing” for better detection of the corrosion while being independent of the state of the surface.
- Precision on the order of 0.1 mm in steel (accuracy dependent on material + material + calibration)
- In some cases (measurements undercoatings for example) it is necessary to visualize the ultrasonic signal.
How an Ultrasonic Thickness Gauge works
To understand the operation of this device, it is necessary to know that ultrasound is the energy of sound at frequencies that exceed the limit of the human ear.
And is that most ultrasound tests are performed in the frequency range between 500 KHz and 20 MHz, and some specialized instruments can operate at 50 KHz or less and 100 MHz or more.
The operation of the Ultrasonic Thickness Gauge is based on determining with high precision what is called flight time, which is the time it takes for a pulse of sound generated by a small probe called an ultrasonic transducer to pass through a piece and return to the device.
At the same time, that transducer contains a piezoelectric element that is stimulated by a short electrical impulse to generate a burst of ultrasonic waves.
It is there that the waves are coupled into the material and pass through it until they find a back wall or other limit and then the reflections go back to the transducer, which converts the acoustic energy into electrical energy.
And with this process, you can measure any common engineering material by using ultrasound and it is possible to configure ultrasonic thickness gauges for metals, plastics, composites, fiberglass, ceramics and glass.
Characteristics of our equipment
- Choice of the translator in a reference list, which allows the use of translators of competing brands.
- Correction of the course in “V.”
- 0.01 mm resolution
- The possibility of creating corrosion profiles: B-SCAN as a function of time with adjustable scrolling speed or encoded BScan profiles
- Measurements of metal thicknesses under paint or coating
- Alarms of different colors of sound, visuals and vibrators
Examples of applications
- Pressure vessel monitoring
- Preventive maintenance on classified installations
- Reception inspection of pipes, sheets …
- Periodic and compulsory inspection of tanks, tanks, …
The latest innovations regarding the thickness
- “EtoE” technology for measuring through coatings
- BScan encoded for thickness measurement
- Visualization of the ultrasound signal (A-Scan)
There are innumerable uses for a thickness gauge by ultrasound.
The great diversity of applications divides the offer of thickness gauges by ultrasound into primarily two large groups: precision gauges and corrosion meters. Each group has its respective types of transducers whose selection, in turn, responds to the measurement mode and the particular application.