Uncertainties in Dimensional Measurements Made at Nonstandard Temperatures

Area of Science:

• Metrology
• Materials Science
• Thermodynamics

Background:

• Dimensional measurements are sensitive to temperature variations.
• Accurate length measurements require accounting for material thermal expansion.
• Deviations from the standard reference temperature (20 °C) introduce uncertainty.

Purpose of the Study:

• To analyze the impact of temperature and thermal expansion uncertainties on length measurement uncertainty.
• To evaluate uncertainties from various sources of thermal expansion coefficients.
• To assess uncertainties in temperature measurement relative to the International Temperature Scale of 1990 (ITS-90).

Main Methods:

• Investigating uncertainties in thermal expansion coefficients from diverse references.
• Examining uncertainties in temperature measurements using different thermometry types.
• Analyzing temperature control levels for ITS-90 realization.

Main Results:

• Quantified expanded uncertainty in length measurements due to thermal effects.
• Identified key contributors to uncertainty from thermal expansion coefficient values.
• Assessed the influence of temperature measurement precision on dimensional metrology.

Conclusions:

• Temperature and thermal expansion uncertainties are critical factors in length dimensional measurements.
• Accurate material property data and precise temperature realization are essential for reducing measurement uncertainty.
• This analysis provides a framework for managing uncertainties in non-standard temperature environments.