Aplikacje

Application Notes

Wall Thickness Measurements for Metal Cans, Containers and Enclosures

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 in. (0.20mm) can be measured with the Model 35DL and Model 38DL PLUS gages and a 20 MHz or 10 MHz delay line transducer to a calibrated accuracy of ±0.0001 in. (±0.001mm). Contact transducers will be used for thicker metal up to 10 in. (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 in. (0 to 1.98mm).

Products used for this application

35DL

The pocket-sized 35DL is a handheld ultrasonic thickness gage for precision measurements on metal, plastic, rubber, glass, and composites using single element transducers. Same features as Model 35 but has internal datalogger.

35DL-HP

The pocket-sized 35DL-HP (High Penetration) is a handheld ultrasonic thickness gage for measurements on thick or sound-attenuating materials such as fiberglass, cast metal, and rubber. Using single element transducers. Same features as Model 35 but has internal datalogger.

38DL PLUS

The 38DL PLUS is an advanced ultrasonic thickness gage. Uses dual element transducer for internally corroded applications, features include THRU-COAT and Echo-to-Echo. Uses single element transducers for very precise thickness measurements of thin, very thick, or multilayer materials.

Magna-Mike 8500

The Magna-Mike is a Hall Effect thickness gage that uses a magnetic probe to perform accurate measurements on nonferrous and thin materials such as plastic bottles. Easy to use, not material dependent, use small target ball that can be placed inside the part.