A N
O span gas having a concentration of 80 to 100 % of full scale to the normal operating range shall be passed through the (H)CLD and the NO value recorded as D. The NO gas shall be bubbled through water at room temperature and passed through the (H)CLD and the NO value recorded as C. The analyser's absolute operating pressure and the water temperature shall be determined and recorded as E and F, respecti
vely. The mixture's saturation vapour pressure that corresponds to the bubbler water temp
...[+++]erature (F) shall be determined and recorded as G. The water vapour concentration (in %) of the mixture shall be calculated as follows: