Structural Probe (Add‑on)

Identify defects, voids, and structural changes inside materials and components

Our unique Structural Probe Measurement Module makes it possible to measure the Thermal Conductivity as a function of depth into a sample using our Hot Disk® sensors. The sample material can be of any type (except a low viscous liquid), for example, a mineral, a layered structure, a composite, or an assembled component. As the ability of a material to conduct heat depends strongly on both material composition and material quality, our Structural Probe Measurement Module offers a simple, non-destructive tool to help identify what materials a layered structure is composed of, inspect the homogeneity of a composite, detect and localize defects, voids, and inhomogeneous substances in a material or component, etc.

Conducting a measurement with the Structural Probe Measurement Module is similar to our Isotropic Measurement Module. The same transient temperature reading is performed, where the thermal probing depth is typically controlled to within the radius of the Hot Disk® sensor. Thus, structural probing can be conducted at depths ranging from sub-millimeter to several centimeters using our smallest and largest diameter Hot Disk® sensors. Both single-sided and double-sided sample testing are supported, where the former enables rapid QC testing while the latter maximizes measurement accuracy. Finally, note that for measurements with the Structural Probe Measurement Module, the Specific Heat Capacity of the sample is required. Suppose it is not found tabulated in scientific papers, etc., or known from previous testing of similar materials. In that case, it can readily and accurately be tested via our dedicated Hot Disk® instrument add-on Specific Heat Capacity Measurement Module.

The Structural Probe Measurement Module’s capabilities make it a powerful tool for non-destructive QC testing in materials processing and components manufacturing industries. Such applications include graphite-epoxy structures, rubber tires, and brake pads. Our non-destructive structural probe technique supplements other techniques to detect and localize defects, voids, and structural changes. For example, ultrasound imaging and optical tomography have limitations on what materials can be probed and what probing depths can be targeted.

We invented this unique structural probe technique, and the theory behind it is presented in our paper published in Review Scientific Instruments in 2016¹. Our paper published in AIP Advances in 2016² discusses and evaluates its practical use.

1. A. Sizov et al., “Thermal conductivity versus depth profiling of inhomogeneous materials using the hot disc technique”, Rev. Sci. Instrum. 87, 074901 (2016).↩︎
2. B. M. Mihiretie et al., “Thermal depth profiling of materials for defect detection using hot disk technique”, AIP Advances 6, 085217 (2016). ↩︎

 

Thermal Conductivity Range:

Instruments	Range
TPS 3500, TPS 2500 S	0.03 to 500 W/m/K