Volume and Density
John D. Wright
Please contact the technical staff before shipping instruments or standards to the address listed below.
NIST provides calibration services for metal volumetric test measures in the range from 3.8 L to 7600 L (1 gallon to 2000 gallons). The procedure used for testing volumetric test measures is to weight the amount of distilled water contained and/or delivered with reference to the graduations marked on the instrument, the volume being computed from the density of the water. The quality of the markings and the care exercised in reading or setting the liquid level are major factors in test calibration and usage.
NIST does not provide routine calibration services for glassware; however, NIST will accept factory standards and replacement glassware for the State Weights and Measures Offices or Departments, in the range of 10-2 L to 5 L, which conform to specified requirements. The technical contacts given above can give guidance on these requirements.
The volumetric test measures which are accepted for calibration should be free from dents, rust, etc. Special care should be taken by the customer to insure the cleanliness of the inside of the test measures. Should the test measure be equipped with a bottom drain valve, it is the customer's responsibility to insure that the valve be in proper working condition. These test measures should bear an inscription which indicates the nominal value of its volume, the thermal coefficient of expansion, an identification number, and its reference temperature. The scale plate should be legible in that the scale division can be estimated to one-tenth of a single division. NIST does not provide a scale calibration. The zero index or the scale should, therefore, be adjusted prior to the calibration. The slicker-plate-type volume standards should be adjusted by the manufacturer.
NIST delivers a calibration report per item tested that includes an uncertainty analysis. The uncertainty of the vessel will depend on its reproducibility and the uncertainty of any instrumentation associated with the determination of the vessel's volume.
NIST provides special tests on volume standards other than those mentioned above. The technical contacts cited above should be contacted regarding testing.
References-Volume and Density Measurements
International Comparison of Volume Measurement Standards at 50 Litres at CENAM (Mexico), PTB (Germany), Measurement Canada, and NIST (USA), J. M. Maldonado R. et al., Metrologia 39 1 (2002).
ASTM Practice E542-00, Standard practice for Calibration of Laboratory volumetric Apparatus, Book of Standards 14.04.
The Equivalence of Gravimetric and Volumetric Test Measure Calibration, R. Schoonover, Natl. Bur. Stand. (U.S.), NBSIR 74-454 (Feb. 1987).
ASTM Specification E694-99, Standard Specification for Laboratory Glass Volumetric Apparatus, ASTM Book of Standards Volume 14.04. (1999).
Calibration of Small Volumetric Laboratory Glassware, J. Lembeck, Natl. Bur. Stand. (U.S.), NBSIR 74-461 (Oct. 1974).
Procedures for the Calibration of Volumetric Test Measures, J. F. Houser, Natl. Bur. Stand. (U.S.), NBSIR 73-287 (Aug. 1973).
Testing of Volumetric Standards, J. C. Hughes and B.C. Keysar, Natl. Bur. Stand. (U.S.), NBS Monograph 62 (Apr. 1963).
Testing of Glass Volumetric Apparatus, J. C. Hughes, Natl. Bur. Stand. (U.S.), NBS Circular 602 (Apr. 1959).