ISO 18653:2003

Overview

ISO 18653:2003 - Gears: Evaluation of instruments for the measurement of individual gears - specifies methods to evaluate gear-measuring instruments used to measure involute profile, helix (lead), pitch and runout. It applies to instruments that measure runout directly and to instruments that compute runout from indexed measurements. The standard also gives recommendations for tooth thickness measurement and requires estimation of measurement uncertainty using calibrated gear artifacts. ISO 18653:2003 is an instrument-evaluation standard; it does not define acceptance criteria for product gears nor does it replace artifact calibration by accredited laboratories (ISO/IEC 17025).

Key topics and requirements

• Scope of measurement: involute, helix, pitch, runout and tooth thickness on individual gears.
• Artifacts: requirements for calibrated artifacts (size, geometry, involute/helix forms, pitch/runout features and workpiece-like artifacts) to transfer traceability and evaluate instrument performance.
• Traceability: unbroken calibration chain from primary laboratories to shop-floor instruments using calibrated gear artifacts; the hierarchy of calibration is emphasized.
• Measurement uncertainty: procedures and methods (including comparator approaches) to estimate uncertainty for the measurement process; guidance that conventional practice aims for measurement uncertainty