Olympus Logo
Olympus LogoOlympus Logo
Application Notes
Back to Resources

Thickness Measurement of Aerospace Composites

In the aerospace industry, many structural components such as wing panels and radomes are made with fiberglass and advanced composites that need accurate thickness control. Composites are often stronger than conventional materials and weigh less. Advanced composites are often made by combining graphite or carbon fibers with epoxy, polyamide, or polyimide resins.

Instant, nondestructive thickness measurements can be made on parts such as wings, fuselage, ducts, panels, and fan blades. Ultrasonic thickness gaging can be done during fabrication or after installation to ensure correct wall thickness.

NOTE: The inherent nature of composite materials can produce varying degrees of anisotropy and therefore sound velocity variation. Care should be taken when evaluating any specific composite application that the sound velocity is sufficiently uniform to permit the required measurement accuracy.

Equipment: Both ultrasonic thickness gages and the Magna-Mike Hall Effect thickness gage can be used for composite thickness measurement.

In general, thickness of most composite materials for aerospace applications in the range of 0.050 in. to 0.750 in. (1.25 to 20 mm) can be measured with the hand-held Model 38DL PLUS or Model 45MG with Single Element Software gages and a selected transducer, commonly an M106 2.25 MHz contact transducer. Certain composites that are very scattering or that are thicker than approximately 0.750 in. (20 mm) may require gages with the HP (high penetration) software option and a lower frequency transducer. In especially challenging cases, waveform display monitoring is recommended to permit on-site operator adjustment of setup parameters.To measure the wall thickness on composite products thinner than 0.125 in. (3 mm), delay line transducers such as the M202 may also be recommended.

If there is access to both sides of the test piece for a probe and a target ball, as in a manufacturing environment, the Magna-Mike 8600 Hall Effect thickness gage can also be used. The Magna-Mike offers the advantage of couplant-free measurements that are independent of sound velocity variations, and with an appropriate probe and targets it can measure up to a maximum thickness of 1.00 in. (25.4 mm).

Olympus IMS

Products used for this application


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


The handheld 45MG ultrasonic thickness gage is packed with measurement features and software options. This unique instrument is compatible with the complete range of Olympus dual element and single element transducers, making this gage an all-in-one solution for virtually every thickness gage application.

Magna-Mike 8600

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.
Sorry, this page is not available in your country

Let us know what you're looking for by filling out the form below.