Photoelectric sound measurement. Replaceable spring for long service life and easy maintenance. Nonmagnetic, wearresistant, antistatic mechanical rotation measurement. Capable of measuring small apertures and narrow grooves. Antimagnetic design applied to the rotary part at the lower end to minimize magnetic interference. Use scenarios Electronics manufacturing and quality control: inspect PCBs and microelectronic housings to verify small holes and narrow slots meet specifications while avoiding magnetic interference with surrounding components. Precision mechanical parts production: measure tiny features such as small apertures and narrow grooves on bearings, shafts, and housings, with a durable, wearresistant rotation mechanism. Laboratory and cleanroom environments: handle staticsensitive components safely, using antistatic design to reduce the risk of discharge during measurement tasks.