This section provides procedures for checking the sample system with a very reactive gas.
This is not a check of the accuracy of the analyser but is a check of the sample system’s
ability to deliver the gas to the analyser without significant losses. If the measurement period
is for a very reactive gas only, it is necessary to use the procedure in 7.4.3 to confirm the
accuracy of the analyser. This shall be carried out using the very reactive gas being
measured or an alternative gas(s). If an alternative gas is used, it is necessary to check the
sample system using the very reactive gas.