GE Sievers 900 Series, Operation And Maintenance Manual

Page: 154 / 236

GE Analytical Instruments ©2009 154 of 236 DLM 90488-01 Rev. A
7. When prompted, remove the Reagent Water from the vial port IOS System, insert the 25
ppm TOC (as KHP) standard, and press Next .
8. When prompted, remove the 25 ppm TOC (as KHP) standard from the vial port IOS System,
insert the 50 ppm TOC (as nicotinamide) standard, and press Next .
9. When prompted, remove the 50 ppm TOC (as nicotinamide) standard from the vial port IOS
System, insert the 25 ppm IC (as Na
2
CO
3
) standard, and press Next
10. The Autoreagent calibration summary screen is displayed (see Figure 28). This screen
presents data obtained during preliminary measurements of the standards. (See page 95
for a description of the preliminary measurement.)
The peak times measured for the 25 ppm and 50 ppm TOC Standards are listed first. The
median peak time for each TOC Standard is used in the Autoreagent calibration. The
difference between the two peak times is a criterion to determine if the Autoreagent
calibration passed or failed. The median peak time of the 50 ppm TOC Standard must be
from 20 to 100 seconds less than the median peak time of the 25 ppm TOC Standard.
The summary screen then lists the measurements made on the 25 ppm IC Standard. Four
measurements of the IC Standard were made after the preliminary measurement. The first
of these is rejected, as in any calibration procedure. The remaining three measurements
are statistically evaluated using the Q-test, and one of those three measurements may be
rejected. The average of the two to three valid measurements is presented as the IC
Expected Concentration. The TC Expected Concentration is calculated the same way. The
RSDs of the valid IC and TC measurements also are listed.
The summary screen lists the average of ten preliminary measurements made at the IC
and TC channels, along with the RSD of those preliminary measurements.
The Analyzer indicates if the Autoreagent Calibration passed or failed based on the
following criteria:
• The median peak time of the 50 ppm TOC Standard is from 20 to 100 seconds less than
the median peak time of the 25 ppm TOC Standard.
• The RSD of the valid expected IC and TC concentration measurements is 3% or less.
• The RSD of the IC and TC preliminary measurements is 5% or less
11. If the acceptance criteria are satisfied, press Apply to accept the Autoreagent calibration
and continue.
12. Remove the 25 ppm IC (as Na
2
CO
3
) Standard from the IOS System.
13. You should now verify the Autoreagent calibration. Proceed to “Performing an Autoreagent
Verification” on page 155 for instructions.