Ocean Optics OOISensors - Manual (Page 133)

C: ph Sensor Theory of Operation and Calculations
Revised Model #4
Looks at base peak only. Corrects for baseline.
lineAbs HighpHBase A
s BaselineAb A
A
HighpHAbs
Abs
−
−
=
−
−
−
] [
] [
] [
] [ 1 ] [ − − = A HA
Then calculate the pK and slope values from…
] HA [
] A [
log * Slope pK pH
−
+ =
…where the two points you are using are the low buffer and high buffer
Then proceed to calculation
If
0
] [
] [
≤
−
HA
A
then 0 = pH
else
] HA [
] A [
log * Slope pK pH
−
+ =
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