GE Analytical Instruments ©2016
107 of 270
DLM 68100-09 EN Rev. A
Chapter 5: Calibration and Verification
For accuracy, the IC standard solution(s) must be prepared just before the calibration. The solutions are basic, so
it will absorb CO
2
from the air. That absorption can significantly change the concentration of the solution. To
minimize the rate of CO
2
absorption, the solution should be stored in a sealed container until use. Just prior to
the IC calibration, a 40-mL vial should be filled with the standard solution.
Calibration and Verification Options
When calibrating the InnovOx On-Line Analyzer using either the Single-Point Calibration or Two-Point
Calibration, the algorithm used to calculate the slope of the calibration curve uses the following variables:
•
The mass response
•
The ratio of sample volume to total volume (where total volume includes sample, dilution water,
reagents, and so on.)
•
The concentration of the standard (e.g., 1000 ppm)
Slope
7
= [(standard concentration) * (V
s
/V
t)
]/(mass response)
Single-Point Calibration
When a single-point calibration is performed, only one standard is used, as shown in
. For that reason,
single-point calibrations are convenient and rapid; however, the analysis of samples may be less accurate than
when other calibration methods are used.
7.
V
S
= Volume of sample in sparger needed for dilution range, mL
V
T
= Total solution volume in sparger, mL
