This classification covers measuring instruments and sensors essential for quality control, process management, and equipment monitoring in manufacturing sites. It includes dimensional measuring tools (calipers, micrometers, height gauges), precision measuring equipment (coordinate measuring machines, surface roughness testers, roundness measuring machines), various sensors (temperature, pressure, flow, vibration, proximity), and inspection equipment (hardness testers, thickness gauges, flaw detectors). This important equipment group directly contributes to quality assurance and productivity improvement in manufacturing processes, and is clearly distinguished from processing machinery and control systems.