BS ISO 12963:2017 pdf free
BS ISO 12963:2017 pdf free.Gas analysis – Comparison methods for the determination of the composition of gas mixtures based on one- and two-point calibration
For screening and exploratory analyses, the approach described in Annex E may be used. It omits the performance evaluation but replaces it by a (in most cases large) worst-case estimate for a possible nonlinearity between the fixed sampling points. It might be useful for the TPC and, if uncertainties arising from the worst-case estimate are not considered to be too large to be feasible, also for the TPB design. The approach may also be used in research into new fields where (certified) calibration gases are not available or do not exist in a sufficient number. Note that this is not covered by this document and Annex E has an informative character only.
From the results of the performance evaluation, estimates according to Formula (13) shall be derived which remain valid until the next instance of the abovementioned case in 8.1 b).
The time of validity of a working calibration according to the approaches of 6.2 shall be determined in a drift/stability control experiment according to 9.2. This will normally be done within the framework of the initial performance evaluation. In this initial performance evaluation phase, independent calibration gases can be used for obtaining a number of control-chart data sufficient for assessing the stability of the system and the period of validity of the working calibration. It is recommended to re-calibrate the system (working calibration) not later than at an instance in time when half of the determined period-of-stability has elapsed.
The above does not apply to exact-match calibration (SPEM) and bracketing using two reference standards (TPC). For these techniques, the exact-match calibration gas or the bracketing calibration gases are to be measured at the time and each time an unknown sample is determined.BS ISO 12963 pdf download.
