BS ISO 7504:2015 pdf download – Gas analysis — Vocabulary
This International Standard defines terms related to gas analysis, with the main focus on terms relatedto calibration gas mixtures for use in gas analysis and gas measurements. lt does not cover terms whichrelate only to specific applications.
The following documents, in whole or in part, are normatively referenced in this document and areindispensable for its application. For dated references,only the edition cited applies. For undatedreferences, the latest edition of the referenced document (including any amendments) applies.
ISO/IEC Guide 98-3:2008,Uncertainty of measurement —Part 3:Guide to the expression of uncertainty inmeasurement (GUM:1995)
ISO/IEC Guide 99:2007,International vocabulary of metrology — Basic and general concepts andassociated terms (VIM)
ISO 10715:1997,Natural gas — Sampling guidelines
3 Terms relating to general concepts
Terms used in the field of gas analysis that are well defined by either ISO/IEC Guide 98-3 orISO/IEC Guide 99 are included in Annex A.
state of a gas mixture wherein all of its components (3.3) are distributed uniformly throughout thevolume occupied by the gas mixture
attribute of a gas mixture, under specified conditions, to maintain its composition(3.5) within specifieduncertainty (Annex A) limits for a specified period of time (maximum storage life(7.5))
chemical entity at a defined physical state present in a material or in a mixture3.4
amount-of-substance fraction (220.127.116.11), mass fraction (18.104.22.168), volume fraction (22.214.171.124), amount-of-substance concentration (126.96.36.199),mass concentration (188.8.131.52), volume concentration (184.108.40.206) of acomponent (3.3) in a gas or gas mixture
Note 1 to entry:See ISO 14912[Z] for further information about this concept.
EXAMPLE1 The hydrogen content in a mixture of hydrogen and nitrogen, expressed as an amount-of-substancefraction ( 220.127.116.11), is x(H2)=0,1.
EXAMPLE 2 The content of sulfur dioxide in air at p = 101,325 kPa and T = 288,15 K, expressed as a massconcentration (18.104.22.168), is v(So2) = 1 mg/m3 .
identity and content (3.4) of each component (3.3) that constitute a particular gas mixture
x B , y B
quotient of the amount of substance of a component B and the sum of the amounts of substance of all components (3.3) of the gas mixture
[SOURCE: ISO 80000-9:2009, 9-14]
quotient of the mass of a component B and the sum of the masses of all components (3.3) of the gas mixture
[SOURCE: ISO 80000-9:2009, 9-12]
quotient of the volume of a component B and the sum of the volumes of all components (3.3) of the gas mixture before mixing, all volumes referring to the pressure and the temperature of the gas mixture
[SOURCE: ISO 80000-9:2009, 9-15]
quotient of the amount of substance of a component B and the volume of the gas mixture
[SOURCE: ISO 80000-9:2009, 9-13]
quotient of the mass of a component B and the volume of the gas mixture
[SOURCE: ISO 80000-9:2009, 9-11.2]
quotient of the volume of a component B before mixing and the volume of the gas mixture, both volumes referring to the same pressure and the same temperature
Note 1 to entry: The volume concentration and the volume fraction (22.214.171.124), both referring to the same pressure and the same temperature, have identical values if, and only if, the sum of the component volumes and the volume of the whole gas mixture are identical.
4 Terms relating to physical properties
equation of state
mathematical relationship between the state variables (pressure and temperature) of a gas or gas mixture and the volume occupied by a given amount of substance, written as pV = ZnRT
Note 1 to entry: In this relationship
p is the pressure;
V is the volume;
Z is the compressibility factor (4.2);
n is the amount of substance;
R is the molar gas constant;
T is the absolute temperature.
quotient of the volume of an arbitrary amount of gas at specified pressure and temperature and the volume of the same amount of gas, at the same state conditions, as calculated from the ideal gas law