An optical sensor using new high-speed “spectral coherence interferometry” can measure the thickness of up to 16 layers in clear coex film with sub-micron accuracy, says Isis Optronics GmbH in Mannheim, Germany.

An optical sensor using new high-speed “spectral coherence interferometry” can measure the thickness of up to 16 layers in clear coex film with sub-micron accuracy, says Isis Optronics GmbH in Mannheim, Germany. Its new StraDex 80/300 S gauge control is limited to 16 layers because of software, not the sensor, Isis says.


The noncontacting infrared (IR) sensor is mounted on a ring circling the bubble and contains both a transmitter and receiver. It can use either of two wavelengths—830 nanometers (near-IR) or 1300 nm (between NIR and IR)—to take up to 4000 measurements a second. Rapid refocusing gives it a working range of 2 to 22 mm, allowing it to measure even a rapidly fluttering bubble, Isis says. The minimum layer thickness it can measure is 5 microns. Absolute accuracy on smooth film is said to be ±0.25 microns. Tel: +49 (621) 842 510 • www.isis-optronics.com