Thermo Fisher Scientific CyberScan pH 5000 - Manual (Page 112)

Instruction Manual CyberScan pH5500/ 5000
Direct Reading with Blank Offset
This method presents you with the ability to measure samples with
low level concentrations of the ion of interest. It eliminates
background interference by subtracting the value of a blank
concentration from the value for the sample. See ISE theory pg 133.
To Standardize the Meter
You will need to standardize the meter with one blank and a minimum
of two standards.
1. Touch
STD on the Ion measure screen to access the standardize
screen.
2. Touch
clear to delete the previous standards.
3. Add ionic strength adjuster to the standards and the blank.
4. Immerse the ion selective electrode in the standard containing
the lowest concentration of the ion of interest.
5. Stir the standard and/ or blank.
6. Touch
std again to initiate the standardization process. At this
point, the meter will display the question” is this standard or a
blank?”
7. Touch
STND if the sample that the electrode is immersed in is an
Ion standard solution.
OR
Touch
BLANK if the sample that the electrode is immersed in is
the blank solution.
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