校正方法論と計量基準
NIST Handbook 44/133、USDA FoodData Central、およびISO/IEC 17025規格に厳密に準拠しています。
Scientific Metrology Framework
Converting volumetric measures into mass requires empirical density values calibrated to temperature, pressure, and container geometry. Pint to Pound models both homogenous fluids and heterogeneous agricultural produce with exact void fractions.
Mathematical Rigor & Floating-Point Integrity
All internal arithmetic is executed with IEEE 754 64-bit double-precision floating-point numbers. Rounding is never applied to intermediate calculation steps, eliminating cumulative truncation errors.
Final displayed values are rounded strictly to significant metrological figures (typically 2 to 4 decimal places) matching certified kitchen scales and laboratory balances.
Temperature & Thermal Expansion Normalization
Liquid density is temperature-dependent. Standard culinary reference density on Pint to Pound is normalized to 20°C (68°F) at standard atmospheric pressure (101.325 kPa), where pure water density is 0.998207 g/mL.
Regulatory & Standards Matrix
ISO/IEC 17025 Traceable| Standard / Body | Technical Scope | Measurement Benchmark | Authority |
|---|---|---|---|
| NIST Handbook 44 | Commercial Weighing & Measuring Devices | Liquid measures graduated tolerance ±1.0% to ±2.0% | US National Institute of Standards & Technology |
| NIST Handbook 133 | Checking the Net Contents of Packaged Goods | Maximum Allowable Variations (MAV) for food packages | US Dept of Commerce |
| USDA FoodData Central | Nutrient Data & Food Density Database | Certified standard food density & proximate compositions | Agricultural Research Service (ARS) |
| OIML R 87 | Quantity of Product in Packages (Global) | International legal metrology packaging tolerances | International Organization of Legal Metrology |
| ISO/IEC 17025 | Testing & Calibration Laboratories | Laboratory measurement traceability and uncertainty budgets | International Organization for Standardization |
| FDA 21 CFR 101.9 | Nutrition Labeling of Food | Household measuring cup defined as 240 mL legally | US Food & Drug Administration |
Frequently Asked Methodology Questions
よくある質問 (FAQ)
パイント、ポンド、密度、測定規格に関する明確で信頼できる回答。