Download 1. SevenMulti - METTLER TOLEDO

The pH/Ion and ISFET expansion units
6.3.2
Operation of the Ion menu
– If two expansion units are attached, first ensure that the desired expansion unit is selected.
– Press Mode and press Ion in the menu that appears to select the ion mode.
– Call up the Ion menu with Menu.
1. Measurement Unit and Stability Criterion
1.
Select Measurement Units
In this menu you can define the unit (mmol/L, mol/L, ppm, mg/L oder %) for measurements and calibration.
– Afterward you can change to mmol/L and mol/L units or ppm, mg/L and % using the menu item 1.1. Measurement setting.
Note: If, for example, you wanted to change from mol/L units to ppm, you must first recalibrate otherwise an
error message appears.
2.
Select Stability Criterion
In this menu you can define the stability criterion of your measurement
Stability criterion for fast
The measured signal may not change by more than 0.3 mV in 4 seconds.
Stability criterion for normal
The measured signal may not change by more than 0.08 mV in 8 seconds.
Stability criterion for strict
The measured signal may not change by more than 0.03 mV in 12 seconds or by more than 0.08 mV in
26 seconds
2. Calibration Setting
1.
Set Calibration Standard
You can define the calibration standards here:
– Select the unit and press Enter to access the table for entering temperature values and ion concentrations.
– Enter values using the alphanumeric keypad, use î to navigate within the table and ë to delete.
– Press Save to end the editing the table and accept the values.
2.
Select Calibration Mode
1. Segmented Method
The segmented method is the most modern method for precise Ion measurements. The calibration curve is
made up of line segments joining the individual calibration points rather than a linear regression through
them. Non-linear behavior frequently occurs at low ion concentrations. The segmented method is preferred
for high-precision measurements.
2. Linear Method
With this method, the calibration curve is determined via a linear regression line. The linear method should
only be used at higher concentrations where the calibration curve is still mainly linear.
METTLER TOLEDO SevenMulti™
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