Measuring the height and pitch of serrated threads (e.g. on thread gauges or precision screws) can be very challenging — especially due to the steep thread angles involved. Standard laser displacement sensors often fail here, as the sharp reflection angles result in missing or weak signals.
That’s where Chromatic Confocal Sensors (CFS) come in.
Thanks to their coaxial optical design, CFS can measure complex angled surfaces with high precision, capturing the full thread profile in a single scan — even on sharp or deep thread shapes like serrated threads.
🧪 Measurement Parameters:
Using the HPS-CFL036 sensor head from Hypersen, the following key thread parameters can be measured:
Major diameter – the outer diameter of an external thread or the inner base diameter of an internal thread
Minor diameter – the base diameter of an external thread or the tip diameter of an internal thread
Pitch diameter – the theoretical cylinder where the thread ridge and groove widths are equal (a key parameter for precision control)
Number of thread lines (starts) – single-thread or multi-thread types
Pitch and lead – the axial distance between two adjacent thread points (equal for single-start threads)
Thread direction – left-hand or right-hand screw direction
Thread height and cross-section – full profile scan showing top and bottom of the thread
🎯 Why Chromatic Confocal?
✅ Works on steep angles (thread slopes > 50°)
✅ High precision: Repeatability up to 0.05 μm
✅ Large tilt tolerance: Sensor head allows mounting angles up to ±35.23°
✅ Non-contact & damage-free
✅ Ideal for metrology, R&D labs, or inline inspection of mechanical components
📸 Real Results:
The thread cross-section shows a sharp and detailed profile, clearly capturing the thread peaks and valleys even on steep-sided thread shapes. This allows accurate and repeatable evaluation of key parameters, especially where standard sensors would fail.
