Calibration
IV-5
Thermo Scientific Orion 2120XP Calcium Hardness Analyzer User Guide
Maximum system accuracy is ensured through a fast, easy and accurate
calibration performed in the expected sample range. This calibration
procedure uses equipment supplied in the calibration kit
(Cat. No. 2120XPCAL).
• Wait at least one hour after changing the reagent or cleaning electrode
before performing a calibration.
• Check that the present sample concentration is equal or less than
standard 1. If not, a calibration can still be performed with a loss in
accuracy as long as background concentration is not significantly larger
than the concentration of standard 1. The best results are achieved
when standard 1 is twice the level of the present sample concentration.
• Proper pipet technique is crucial to the calibration. If the operator is
not familiar with pipet equipment or technique, refer to the
Appendix,
Pipet Operation
section.
• Do not touch the pipet tip with bare fingers. Risk of contamination is
possible. Use powder free gloves to prevent contamination.
• When using a pipet to inject standards during calibration, use a fresh
pipet tip for each standard and each injection.
• When a fresh tip is installed, rinse the tip with the same concentration
standard as the intended injection.
• Fill the tip and dispense the standard 1 to 3 times before injecting the
standard into the flow cell.
Be sure to discard the standard in the
drain between the rinses.
• Wipe any excess liquid from the outside of the tip with out touching
the opening.
• Insert the pipet tip into calibration port on flow cell cap.
• Be sure to hold the pipet completely vertical while dispensing. Do not
inject the standard on the side of the flow cell, as a film may be retained
on the inside of the wall, resulting in errors in precision of calibration.
Refer to
Figure IV-4
.
Before Performing
a DKA Calibration
Figure IV-4
Pipet Dispensing
Recommendations
