Abstract: To optimize the measurement of metal′s linear expansion coefficient, a lever system combines Fraunhofer single-slit diffraction with thermal expansion. The small expansion is reflected in diffraction fringe changes, while Phyphox collects real-time data, enabling precise measurements. This setup improves accuracy, reduces costs, and enhances students′ innovation and practical skills. 

Key words: metal expansion coefficient, single-slit diffraction, Phyphox, physics experiment.