ISO 19702:2006 pdf download.Toxicity testing of fire effluents —Guidance for analysis of gases and vapours in fire effluents using FTIR gas analysis.
It is not proposed to discuss these techniques, as they are exiremely complex, In essence, they use a number of mathematical models and processes to combine the spectra of known or suspected interferences to match the fire gas spectrum. The spectrum of the specified gas is then Identified and the gas quantified using correction curves to allow for any non-linearity in the response of the FTIR.
These methods require the interferences to be identified within the analysis method or selected Iron, a large database of spectra by the analytical method.
7.2.1 General observations
It is possible to develop FTIR analysis methods to provide good levels of accuracy, especially for a single gas or for a simple mixture of known gases but it must be acknowledged that as the complexity of the gas mixture increases and the number of known and unknown interferences are increased, then the accuracy of the FTIR analysis can decrease In practice, It may be desirable to use a combination of both univarlate and multivarlate methods to analyse fire gas samples which Inherently contain a large number of gases, many of which may be unknown or even unexpected
it is increasingly common for most spectroscopic software packages to include most of the methods listed above, The calibration procedure will therefore depend on the requirements of the method selected and the software package being used.
8 Test start-up
Before a test, the sampling system and gas sampling cell are heated to their chosen working temperatures. Ample time should be allowed for temperature equilibration of the whole sampling system. A new or clean filter should be used when determining acid gases. The throughput of the IR beam shall be checked to ensure correct performance of the spectrometer and suitable wave number reproducibility. A background reference spectrum is obtained.
These methods require the interferences to be identified within the analysis method or selected Iron, a large database of spectra by the analytical method.
7.2.1 General observations
It is possible to develop FTIR analysis methods to provide good levels of accuracy, especially for a single gas or for a simple mixture of known gases but it must be acknowledged that as the complexity of the gas mixture increases and the number of known and unknown interferences are increased, then the accuracy of the FTIR analysis can decrease In practice, It may be desirable to use a combination of both univarlate and multivarlate methods to analyse fire gas samples which Inherently contain a large number of gases, many of which may be unknown or even unexpected
it is increasingly common for most spectroscopic software packages to include most of the methods listed above, The calibration procedure will therefore depend on the requirements of the method selected and the software package being used.
8 Test start-up
Before a test, the sampling system and gas sampling cell are heated to their chosen working temperatures. Ample time should be allowed for temperature equilibration of the whole sampling system. A new or clean filter should be used when determining acid gases. The throughput of the IR beam shall be checked to ensure correct performance of the spectrometer and suitable wave number reproducibility. A background reference spectrum is obtained.
