Aluminum cans used in the beverage industry are routinely inspected for wall thickness. The "old-fashioned" way entailed cutting them up and then measuring the wall manually. With ultrasonic gauging wall thickness can be measured instantly and digitally by simply coupling ultrasound into the part from the outside. Manual measurements are usually fairly straight forward. Automatic or semi-automatic measurements can be complicated by container geometry, which may require sophisticated fixturing to maintain sound beam alignment with respect to the test piece.
Quality control of deep drawn metal containers, such as heart pacemaker enclosures, can benefit greatly from ultrasonics. Radiused edges of these enclosures can get very thin and are critical areas for accurate thickness measurements.

Equipment: In general, wall thicknesses greater than 0.008 inch (0.20mm) can be measured with the Model 35DL and a 20 MHz or 10 MHz delay line transducer to a calibrated accuracy of ±0.0001 inch (±0.001mm). Contact transducers will be used for thicker metal up to 10 inches (250mm) or more. Transducer selection will depend on the exact application. The Model 35 gage can also be used in situations where data logging is not required.
It should be noted that the thickness of aluminum and titanium parts (containers) can also be measured with the Panametrics-NDT MAGNA-MIKE® Model 8500. This instrument utilizes the Hall effect to provide thickness measurements on any non-magnetic material in the range of 0 to 0.098 inch (0 to 1.98mm).

Products used for this application

35 Series
General purpose, lightweight Panametrics-NDT gauges feature optional live Waveform and Adjust Mode. 35DL and 35DL-HP have alphanumeric data logger.

Magna Mike 8500
Primarily for blowmolded plastic bottles and non-ferrous materials. This easy to use Panametrics-NDT gauge uses the Hall Effect magnetic method. Has alphanumeric datalogger.