Table 2. Sequence of Procedures Applied during the Determination of the Sensitivity and Cross-Sensitivity Parameters.

	measured parameter	applied gas generator	supplementary data required	the procedure for generating the required supplementary data
step 1	14NH3 sensitivity	mass-flow controller	none	none
step 2	15NH3 sensitivity	chemical reaction	actual value of c(15NH3)	c(15NH3) is determined in two steps:
				(1) determination of c(14NH3) from the measured value of PA14 with the help of the 14NH3 sensitivity parameter determined in Step 1
				(2) calculation of c(15NH3) from c(14NH3) by using the mixing ratio of the isotope labeled salts
step 3	15NH3 cross sensitivity	mass-flow controller	actual value of c(14NH3)	c(14NH3) is calculated from the measured value of PA14 with the help of the 14NH3 sensitivity parameter determined in Step 1
step 4	14NH3 cross sensitivity	chemical reaction	actual value of c(15NH3)	c(15NH3) is calculated from the measured value of PA15 with the help of the 15NH3 sensitivity parameter determined in Step 2