Calibration; Equipment Required; Two Point Calibration; Single Point Calibration - Tintometer Lovibond SensoDirect pH110 Mode D'emploi

4. Calibration

4.1 Overview
The meter is supplied with calibration by mV signal that simulates an ideal pH electrode mV
output (0 mV at pH 7, based on 25°C working temperature). However, because most pH
electrodes do not exactly replicate the ideal electrode and because the working temperature
may differ from 25°C, it is necessary to calibrate the instrument to ensure measurement ac-
curacy of the combined pH electrode.

4.2 Equipment Required

1. Combination pH electrode
2. pH 4 (or pH 10) & pH 7.0 buffer solutions

4.3 Two Point Calibration

1. Connect the pH electrode to the BNC socket (Figure 1, 5) and immerse in pH 7 buffer
solution.
2. Switch the instrument on by pressing the Power ON Button (Figure 1, 2).
3. Adjust „pH 7 Adjust „ (Figure 1, 6) until the display reads exactly pH 7.00.
4. Rinse the electrode in distilled water.
5. Place the electrode into buffer pH 4 (or pH 10) solution.
6. Adjust slope pH 4 (or pH 10) (Figure 1, 7) until the display reads exactly pH 4.00 (or pH 10.00).
7. Rinse the electrode in distilled water.
8. Repeat steps 3. to 7. at least twice.

4.4 Single Point Calibration

1. Connect the pH electrode to the BNC socket and immerse in a standard buffer solution
(eg pH 7.0).
2. Switch the instrument on by pressing the Power ON Button (Figure 1, 2).
3. Adjust the "pH 7 Adjust „ (Figure 1, 7) until the display reads the same value as the stan-
dard buffer solution used.
5. Taking Measurements
After calibration, the unit is ready for taking measurements.
1. Connect the pH electrode to the BNC socket.
2. Switch the instrument on by pressing the Power ON Button.
3. Immerse the electrode in the solution being measured; the instrument will display the pH
value.
4. During measurement, pressing the Data Hold Button (Figure 1, 4) will freeze the display.
At the same time the display will show a Data Hold indicator. To release the display freeze
function, press the Data. Hold Button again; the Data Hold indicator will disappear from
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SensoDirect 110