Hole Expansion Ratio (HER) Optical Tracking System

This is a dedicated optical metrology system designed to adapt to any HER testing machine (dedicated or FADI-AMT retrofit setups) in order to enable complete Hole Expansion Ratio (HER) test monitoring, tracking, replaying as well as post-test image analysis. This is a complete hardware, as well as software, both optimized for HER testing, and have been verified to operate accurately with high repeatability for a wide range of steels and advanced high strength steel sheets.

General Specifications:

  • Adaptability: Most universal load frames (20kN or higher) with modern electronics and an I/O card (INSTRON, ZwickRoell) as well as most servohydraulic presses (Interlaken)
  • Camera Resolution: ~8Megapixel and 20Megapixel Cameras are available
  • Field of View: up to 36x36mm
  • Depth of Field:up to 16mm
  • Lighting: Integrated LED
  • Max. Frame Rate*: ~50 frames/s
  • Mounting:
    • Fixed Frame
    • Electromechanical 1-Axis Stage
    • Electromechanical 3-Axis Stage


  • Very economical option to perform HER testing and enables utilization of existing load frames
  • Easy to use and robust optical tracking system to enable testing in a real-time mode, as well as image processing in an ex-situ mode.
  • Optical tracking system enables accurate and repeatable tracking of the growing hole diameter (including automatic measurement of the HER value and springback compensation) (tested on a wide range of materials)
  • Optical tracking system enables accurate and repeatable crack detection (tested on a wide range of materials)

HER Optical Tracking System in Use: