The PNR 12 automatically measures the resistance a material provides to being pierced by a specifically shaped test body. The harder the test material, the more pointed and needle-like the test body should be.
Various test kits are available for different products and standards or manual and automatic surface detection. The choice of the accessories depends on the consistency and conductivity of the sample.
Oxa named autonomy provider for SAMS project
I saw this kind of system working in Holland well over a decade ago. It seemed to work well. Best of luck for the project.