ISO 7504 pdf download – Gas analysis – Vocabulary

ISO 7504 pdf download – Gas analysis – Vocabulary.
7 Terms relating to storage In gas cylinders
7.1
maximum filling pressure
pressure up to which a gas mixture can be compressed into a cylinder
Note Ito entry: The maximum acceptable tilling pressure of a gas mixture is limited by the confirmed pressure resistance of the cylinder and the ability of the gas (mixture) to display condensation.
7.2
minimum pressure of utilization
pressure ala gas mixture within a cylinder below which the properties of interest cannot be warranted to lie within their limits
Note I to entry: The minimum pressure of utilization is set with regard to the potential for alteration of the composition (15) of the gas mixture, by either
a) desorption of the component (13) of interest, or
b) desorpt ion of other substances, such as water, from the Inner surface of the cylinder.
7.3
minimum applIcable temperature
temperature below which the properties stated for a gas mixture cannot be warranted to lie within their limits
Note 1 to entry: The minimum applicable temperature is set with regard to its potential for alteration of the
compositIon (15) of thy gas mixture by. for example:
a) sorption of one or more componerit (3.3) by the inner surface of the cylinder
b) condensation of one or more components.
7.4
maximum applicable temperature
temperature above which the properties stated for a gas mixture cannot he warranted to lie within their limits
Note 1 to entry: The maximum applicable temperature is set with regard to its potential for alteration of the composition (15) of the gas mixture by physical or chemical interactions of the components (3.3) with each other or with the inner surface nithe cylinder.
maximum storage life
period after which the properties stated for a gas mixture cannot be warranted to lie within their limits
Note I to entry: This period Is usually identified as that for which the producer assures that the gas mixture maintains Ks composition (3.5) within the specified limits when it Is stored in accordance with the requirements based upon the concepts defined in LI. to 2.4,
Note 2 to entry: The end of this period may be indicated by an expiry date (see also ISO 6142-1111).
8 Terms relating to gas analysis
8.1
gas analytical system
equipment including gas handling and sampling system designed for gas composition measurement
8.2
sampling
terms and definitions related to sampling are included in Annex B
8.3.1
analytkal unit
analyser
assembly which enables qualitative and/or quantitative determinations (measurements) of substances on the basis of their chemical or physical properties
Note ito entry: A typical assembly can comprise
— lines permitting the Introduction and removal of a sample and/or cahbratIon gas(es),
— a measuring cell which, from the physical or chemical properties of the components (13) present in the sample, gives signals allowing their identification or measurement, and
— signal processing devices (e.g. amplifiers, integrators, recorders) and/or data proccssing devices,
83.2
response
output signal of a measuring system
8.3.3
quantification limit
lowest value of which an instrument is able to quantify the content (3.4) of a component (3,3)
Note 1 to entry: The ability to quantity is generally expressed in terms of a component-content (true) value that produces estimates having a specified uncertainty (Annex A).
8.4 Calibration
8.4.1
calibration function
mathematical description of the relationship between component content (3.4) and response (8.12) established by calibration, expressing response as a function of content
8.4.2
analysis function
the inverse of the calibration function (8.4.1). expressing component content (3.4) as a function of response (8.12)
8.4.3
calibration point
pair of values attributed to the component conlen( (3.4) and the corresponding response (8.12)
8.5 Calibration methods
8.5.1
multipoint calibration
establishment of a calibration function (8.4.1) using more than two calibration points (8.4.3) establishing a range within which the values of the camponent Content (14).