Standard Solution & ISA

Measure standard solution in ascending order of ion concentration to create calibration curves in the meter.
Perform calibration once every day or before measurement as appropriate.
It is recommended to delete the former calibration data.  About the procedure, refer to the instruction manual for WQ-300 series.

Add ISA to both standard solutions and sample solution. The volume ratio shall be the following.

Standard solution : ISA = 50 : 1
* About F-, standard solution : ISA = 1 : 1

Notes

• Prepare at least 2 types of standard solution with different concentrations.
• Prepare standard solutions which have the following concentration relationship for calibration. Standard solution with low concentration < Sample solution < Standard solution with high concentration. In this case, prepare 2 standard solutions so that concentration of one of 2 standard solutions is approximately 1/10 of that of the other standard solution.
• Always use new standard solution for calibration.
• After the standard solutions and ISA included in the package are used up, use the standard solution (500 mL) and ISA (500 mL) available as consumables.
• It is best to control the stirring speed so that the stir bar will rotate 3 or 4 turns per second. If swirling occurs on the surface, the stirring speed is too fast. Reduce the speed to a level where swirling does not occur.

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