Abstract: The micro-and-deep aperture measurement method on length measuring machine using high accuracy inductance transducer and ruby probe is introduced. This method can measure the micro-and-deep aperture range from Φ1mm toΦ5mm and below 40mm height.When the confidence probability is 95%, the measurement uncertainty of this device is 0.6μm. The analysis result can meet these demands of measurement.

Key words: Measurement of micro-and-deep aperture, Inductance sensor, Ruby probe