[{"n": "Metrology", "u": "/e/metrology/metrology/", "s": "The science of measurement, from ancient cubits to quantum standards."}, {"n": "International System of Quantities", "u": "/e/metrology/international-system-of-quantities/", "s": "The standard system of quantities underlying the SI, codified in ISO/IEC 80000."}, {"n": "International Prototype of the Kilogram", "u": "/e/metrology/international-prototype-of-the-kilogram/", "s": "The object that defined the kilogram for 130 years."}, {"n": "Caesium standard", "u": "/e/metrology/caesium-standard/", "s": "The caesium standard is a primary frequency standard that works by using the absorption of photons during tran"}, {"n": "Coherence (units of measurement)", "u": "/e/metrology/coherence-units-of-measurement/", "s": "A system where derived units are products of base units with no conversion factors."}, {"n": "Conversion of units", "u": "/e/metrology/conversion-of-units/", "s": "Technique for changing units using multiplicative conversion factors."}, {"n": "Dimensional analysis", "u": "/e/metrology/dimensional-analysis/", "s": "Method for analyzing physical dimensions of quantities."}, {"n": "Buckingham pi theorem", "u": "/e/metrology/buckingham-pi-theorem/", "s": "Theorem restating physical equations using dimensionless parameters."}, {"n": "Comparison of the imperial and US customary measurement systems", "u": "/e/metrology/comparison-of-the-imperial-and-us-customary-measurement-systems/", "s": "Two measurement systems with a common origin but distinct differences."}, {"n": "Imperial and US customary measurement systems", "u": "/e/metrology/imperial-and-us-customary-measurement-systems/", "s": "Two related systems of measurement derived from English units."}, {"n": "English units of measurement", "u": "/e/metrology/english-units-of-measurement/", "s": "English units preceded Imperial and US customary systems."}, {"n": "International yard and pound", "u": "/e/metrology/international-yard-and-pound/", "s": "Agreement defining yard and pound in metric terms."}, {"n": "Centimetre–gram–second system of units", "u": "/e/metrology/centimetre-gram-second-system-of-units/", "s": "Metric system variant using centimetre, gram, and second."}, {"n": "Foot–pound–second system of units", "u": "/e/metrology/foot-pound-second-system-of-units/", "s": "A system of units based on foot, pound, and second."}, {"n": "MKS units", "u": "/e/metrology/mks-units/", "s": "Coherent measurement system that evolved into the International System of Units."}, {"n": "Geometrized unit system", "u": "/e/metrology/geometrized-unit-system/", "s": "A unit system setting c and G to unity for relativity."}, {"n": "Heaviside–Lorentz units", "u": "/e/metrology/heaviside-lorentz-units/", "s": "Rationalized CGS-based units eliminating 4π from Maxwell's equations."}, {"n": "Atomic units", "u": "/e/metrology/atomic-units/", "s": "A system of natural units for atomic physics, based on fundamental constants."}, {"n": "Astronomical system of units", "u": "/e/metrology/astronomical-system-of-units/", "s": "A conventional system for astronomical measurement, adopted by the IAU."}, {"n": "Apothecaries' system", "u": "/e/metrology/apothecaries-system/", "s": "Historical medical weight and volume system used by apothecaries."}, {"n": "Biblical and Talmudic units of measurement", "u": "/e/metrology/biblical-and-talmudic-units-of-measurement/", "s": "Ancient Israelite measurement system still used in Orthodox Jewish law."}, {"n": "Chinese units of measurement", "u": "/e/metrology/chinese-units-of-measurement/", "s": "Traditional Han Chinese measurement system, still used in modified forms."}, {"n": "Japanese units of measurement", "u": "/e/metrology/japanese-units-of-measurement/", "s": "Traditional Japanese measurement system still used in carpentry and agriculture."}, {"n": "Korean units of measurement", "u": "/e/metrology/korean-units-of-measurement/", "s": "Traditional Korean system of measurement, still used informally."}, {"n": "Cooking weights and measures", "u": "/e/metrology/cooking-weights-and-measures/", "s": "Systems for specifying ingredient quantities vary by region and era."}, {"n": "Avoirdupois", "u": "/e/metrology/avoirdupois/", "s": "The everyday system of weights using pounds and ounces, standardized internationally in 1959."}, {"n": "Approximate measures", "u": "/e/metrology/approximate-measures/", "s": "Approximate measures: units of volume without official definition, rooted in tradition."}]