Mass

Test Process that measures a gas’s density as defined by the amount of mass present in a specified volume of gas at a given temperature and pressure. Gases are extremely responsive to temperature and pressure, causing their densities to change rather quickly. Measuring the density of gas the Ideal Gas Law (P*V = nRT) must be taken into account. ** Includes non-uniformity

Test Process that measures a liquid’s density as defined by the amount of mass present in a specified volume of liquid at a given temperature. Temperature affects density, as does the pressure to the extent that the liquid compresses. In, liquids deemed sufficiently incompressible, the volume does not depend on pressure. ** Includes non-uniformity and voids (if any)

Test Process that measures a solid’s density as defined by the amount of mass present in a specified volume temperature. Temperature affects density as solids expand and contract according to their temperature coefficients. ** Includes voids and non-uniformity

Test Process that measures a gas’s density as defined by the amount of mass present in a specified volume of gas at a given temperature and pressure. Gases are extremely responsive to temperature and pressure, causing their densities to change rather quickly. Measuring the density of gas the Ideal Gas Law (P*V = nRT) must be taken into account. ** Includes non-uniformity

Test Process that measures a liquid’s density as defined by the amount of mass present in a specified volume of liquid at a given temperature. Temperature affects density, as does the pressure to the extent that the liquid compresses. In, liquids deemed sufficiently incompressible, the volume does not depend on pressure. ** Includes non-uniformity and voids (if any)

Test Process that measures a solid’s density as defined by the amount of mass present in a specified volume temperature. Temperature affects density as solids expand and contract according to their temperature coefficients. ** Includes voids and non-uniformity

Test Process that measures the Force as defined as mass times acceleration (F = m * a). The formula describes a free mass or the net force on any mass. Dead-weight force measurements depend on true mass, specific location’s influences, such as local gravity, air buoyancy, and material density are often needed. Equal but opposite forces counteract to cancel any net motion or acceleration, but result in a deformation of the objects which can be measured. This test process is typically used to calibrate devices like primary deadweight standards and transfer standards. When measuring the mass of a physical object See Measure.Mass.True

Test Process that measures the conventional value of the result of weighing a body in air equals the mass of a standard that balances this body under the following conventionally chosen conditions: ambient temperature 20 °C air density 1.2 mg/cm³ mass density 8.000 g/cm³ Conventional mass has the same unit as mass (the kilogram), because the multiplication of a mass by a dimensionless quantity defines its values. Labs typically measure mass and correct the results from actual to conventional conditions. “Apparent Mass versus 8.0 g/cm³” formerly equated to conventional mass in the United States. References: NISTIR 6969 (2019) https://www.nist.gov/publications/nistir-6969-selected-laboratory-and-measurement-practices-and-procedures-support-1 OIML D28 (2004) https://www.oiml.org/en/files/pdf_d/d028-e04.pdf NIST Handbook 44: https://www.nist.gov/pml/weights-and-measures/publications/nist-handbooks/other-nist-handbooks/other-nist-handbooks-2-3

Test Process that measures the quantity of matter which a body contains, as measured by its acceleration under a given force or by the force exerted on it by a gravitational field. The term “mass” is always used in the strict Newtonian sense as a property intrinsic to matter. Mass is the proportionality constant between a force on a material object and its resulting acceleration. This property is sometimes referred to as “true mass”, “vacuum mass”, or “mass in a vacuum” to distinguish it from conventional [apparent] mass. The true quantity of matter represented in a vacuum with no gravitational force.

Test Process that measures the relative density, or specific gravity, is the ratio of the density (mass of a unit volume) of a substance to the density of a given reference material. Specific gravity for liquids is nearly always measured with respect to water at its densest (at 4 °C or 39.2 °F); for gases, air at room temperature (20 °C or 68 °F) is the reference. The term “relative density” is often preferred in scientific usage. It is defined as a ratio of the density of a particular substance with that of water.

Test Process that measures the relative density, or specific gravity, is the ratio of the density (mass of a unit volume) of a substance to the density of a given reference material. Specific gravity for liquids is nearly always measured with respect to water at its densest (at 4 °C or 39.2 °F); for gases, air at room temperature (20 °C or 68 °F) is the reference. The term “relative density” is often preferred in scientific usage. It is defined as a ratio of the density of a particular substance with that of water.

Test Process that sources a gas’s density as defined by the amount of mass present in a specified volume of gas at a given temperature and pressure. Gases are extremely responsive to temperature and pressure, causing their densities to change rather quickly. Measuring the density of gas the Ideal Gas Law (P*V = nRT) must be taken into account. ** Includes non-uniformity

Test Process that sources a liquid’s density as defined by the amount of mass present in a specified volume of liquid at a given temperature. Temperature affects density, as does the pressure to the extent that the liquid compresses. In, liquids deemed sufficiently incompressible, the volume does not depend on pressure.

Test Process that sources a solid’s density as defined by the amount of mass present in a specified volume temperature. Temperature affects density as solids expand and contract according to their temperature coefficients. ** Includes voids and non-uniformity

Test Process that sources a gas’s density as defined by the amount of mass present in a specified volume of gas at a given temperature and pressure. Gases are extremely responsive to temperature and pressure, causing their densities to change rather quickly. Measuring the density of gas the Ideal Gas Law (P*V = nRT) must be taken into account. ** Includes non-uniformity

Test Process that sources a liquid’s density as defined by the amount of mass present in a specified volume of liquid at a given temperature. Temperature affects density, as does the pressure to the extent that the liquid compresses. In, liquids deemed sufficiently incompressible, the volume does not depend on pressure.

Test Process that sources a solid’s density as defined by the amount of mass present in a specified volume temperature. Temperature affects density as solids expand and contract according to their temperature coefficients. ** Includes voids and non-uniformity

Test Process that sources a Force as defined as mass times acceleration (F = m * a). The formula describes a free mass or the net force on any mass. Dead-weight force measurements depend on true mass, specific location’s influences, such as local gravity, air buoyancy, and material density are often needed. Equal but opposite forces counteract to cancel any net motion or acceleration, but result in a deformation of the objects which can be measured. This test process is typically used to calibrate devices like load cells, multi-axis transducers, proving rings, force gauges, traction dynamometers, crane scales, bolt testers, aircraft scales, load cell washer, truck wheel load scales, miniature load cells, handheld force gauges, etc. When sourcing mass of a physical object See Source.Mass.True

Test Process that sources a conventional value of the result of weighing a body in air equals the mass of a standard that balances this body under the following conventionally chosen conditions: ambient temperature 20 °C air density 1.2 mg/cm³ mass density 8.000 g/cm³ Conventional mass has the same unit as mass (the kilogram), because the multiplication of a mass by a dimensionless quantity defines its values. Labs typically measure mass and correct the results from actual to conventional conditions. “Apparent Mass versus 8.0 g/cm³” formerly equated to conventional mass in the United States. References: NISTIR 6969 (2019) https://www.nist.gov/publications/nistir-6969-selected-laboratory-and-measurement-practices-and-procedures-support-1 OIML D28 (2004) https://www.oiml.org/en/files/pdf_d/d028-e04.pdf NIST Handbook 44: https://www.nist.gov/pml/weights-and-measures/publications/nist-handbooks/other-nist-handbooks/other-nist-handbooks-2-3