Smart Cuvettes Instructions
SC-PH-VIS1M-SAM-01-1109 7
Algorithms Used
pH Calculation
SamplepH
Sample
AbsAbs
Abs
SlopepKpH
11
log*
…where Abs
Sample
is the sample absorbance at 620nm with baseline correction, and Abs
pH11
is the
absorbance at pH 11 at 620nm with baseline correction.
Temperature Compensation
When you select Use Factory Calibration in SpectraSuite, the value for pK is adjusted via the van’t
Hoff equation based on the current temperature you entered:
12
12
11
*480
12
11
*480
12
log
log
TT
TT
epHpH
epKpK
Resetting pK and Slope
An x-y plot is made using data obtained from intermediate buffers 5 through 8. The x-axis is of the
term:
SamplepH
Sample
AbsAbs
Abs
11
log
…for each of the buffers. The y-axis shows the pH value of the buffers. This generates a plot such as
the one shown below:
