Tribology testing with 3-axis force sensor

Client

This project involves a mechanical testing laboratory specializing in the characterization of materials and coatings. Its activities cover demanding industrial sectors such as aeronautics, automotive, and medical equipment, where precise measurement of friction forces is critical for validating the durability and performance of components. The laboratory uses dedicated test benches, subject to standardized protocols to ensure repeatability and traceability of results.

Problem and challenges

The client faced two major limitations with its existing system, based on two single-axis sensors:

• Implementation complexity: Using two separate sensors (one for horizontal forces, one for vertical force) required precise mechanical alignment and synchronized software processing, leading to errors and increased setup time.
• Measurement limitations: It was impossible to simultaneously capture the three force components (X, Y, Z) in a single acquisition, which distorted the analysis of multidirectional friction phenomena (e.g., lateral sliding or combined forces).
• Technical objectives:
  • Simplify the architecture by replacing the two sensors with a single solution.
  • Improve accuracy with synchronized 3-axis measurement (±0.1% of full scale).
  • Automate data acquisition via an interface compatible with existing processing tools (CSV export, real-time visualization).

PM Instrumentation solution

PM Instrumentation proposed a turnkey solution centered on:

• The K3D40 sensor: A 3-axis force sensor (range 2 N to 50 N) installed between the test bench arm and the sample under test. Its compact design (∅40 mm) and high rigidity minimize mechanical interference, while its differential analog output ensures immunity to electrical noise.
• The GSV-6T3 module: A CAN Bus acquisition electronics configured to:
  • Digitize signals from the 3 axes with 24-bit resolution.
  • Transmit data in real time to a PC via shielded cabling, with a throughput adapted to test dynamics (up to 1 kHz).
  • Integrate the BlueDAQ software (provided) for graphical visualization, data recording, and export.
• Operating principle: The K3D40 sensor measures forward/backward (X), lateral (Y), and vertical (Z) forces applied to the sample during its movement on the platform. Weights added to the arm generate a controlled normal force (Z), while relative motion produces the X and Y components. Raw data is processed by the GSV-6T3 and displayed as superimposed curves for correlated analysis.

Results and client benefits

• Time savings: 40% reduction in test preparation time by eliminating mechanical adjustments and simplifying software configuration.
• Enhanced precision: Simultaneous 3-axis measurement enabled the detection of previously unidentified asymmetric friction phenomena, improving the reliability of test reports.
• Flexibility: The system now supports dynamic protocols (e.g., speed or load variations) with minimal latency (< 5 ms).
• Added value for the end client: The laboratory can now offer more comprehensive tests (e.g., real-time force couple analysis), justifying a premium pricing for its services.