Benchtop pH/ISE Meter Instruction Manual
Determining Isopotential Points
124
Determining an Isopotential Point
1. Prepare several standards with concentration ranges over the
measuring range of the electrode.
2. Measure the millivolt value of the standards at room temperature,
i.e. 20-25°C.
3. Measure the millivolt value of each standard at 75°C.
4. Measure the millivolt value of each standard at 10°C.
5. On semi-logarithmic graph paper, plot the concentration values on
the log axis versus the millivolt values on the linear axis, as any
calibration curve would be drawn (see Figure on previous page).
6. The lines will intersect at the isopotential point. Read the
concentration off the graph for this point from the log axis. This
value is the isopotential point.
7.
See previous instructions on how to adjust the isopotential point on
the Model 920Aplus.
Summary of Contents for 410Aplus
Page 3: ...2 Benchtop pH ISE Meter Instruction Manual...
Page 81: ...80 Benchtop pH ISE Meter Instruction Manual Certificate of Conformity...
Page 89: ...Benchtop pH ISE Meter Instruction Manual Ordering Information 88...
Page 101: ...Benchtop pH ISE Meter Instruction Manual Overview of Meter Functions 420Aplus 710Aplus 100...
Page 117: ...Benchtop pH ISE Meter Instruction Manual Meter Default 116...
Page 119: ...Benchtop pH ISE Meter Instruction Manual Multipoint Calibration Curve 118...
Page 123: ...Benchtop pH ISE Meter Instruction Manual Automatic Blank Correction 122...
