Thermo orion 410Aplus, Инструкция по эксплуатации

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Benchtop pH/ISE Meter Instruction Manual
Calibration and Measurement of Concentration 32
Slope
Up to a five point calibration may be performed. The instrument uses a
point-to-point calibration scheme. The meter stores, in memory, the
different electrode slopes for each portion of the calibration curve. When
measuring in a particular region of the curve, the electrode slope for that
region is employed in the calculation of sample concentration. The
electrode slope, displayed after calibration, is the average slope for all the
segments of the entire calibration curve. Use of this scheme increases
accuracy in the different regions of the calibration curve. However, the
electrode slope displayed may be lower than normal, especially if standards
close to the electrode limit of detection are used in the calibration.
Autoblank Correction
Blank correction occurs automatically when calibrating with three or more
standards. This feature automatically calculates and corrects for
background levels of the species of interest. The standards used for
calibration do not need to include a blank. This improves the results
because typical blanks contain low levels of the species to be measured,
making them unstable and difficult to measure accurately. To take
advantage of this feature select three or more standards for calibration. If
the profile of the calibration curve does not indicate a background level of
ion concentration, then blank correction will not be invoked and the
standard point-to-point scheme will be used. Refer to Appendix D for more
detailed information.