Industrial Low Coherence Interference Measurement: A  Non-Contact and High Precision Measurement Technique of Industrial Parts

Abstract

Low coherence interference is a non-contact measurement method renowned for its high precision, absolute measurement capability, and minimal object damage. Despite its widespread adoption in fields such as biological tissue tomography, its application for measuring industrial parts remains limited due to factors like cost, measurement range limitations, and complex reflection conditions on industrial surfaces.In this paper, we present an improved coherence interference technique designed specifically for industrial parts measurement.Our approach replaces the high-precision phase shifter with a cost-effective guide rail equipped with a grating ruler. This modification significantly reduces costs and extends the measurement range.Additionally, we introduce a high-speed and robust demodulation method for low coherence interference signals.Extensive experimental results validate the effectiveness of our measurement system, demonstrating its exceptional robustness in dealing with diverse reflection conditions in industrial settings. With an optimal accuracy exceeding 6 microns, our system proves highly suitable for measuring a wide range of industrial parts.

Keywords: Non-contact measurement, measurement of industrial parts, low coherence interference