During the process of potentiometric titration, with the addition of titrant, a chemical reaction occurs in the solution, and the concentration of the measured ion continuously changes, resulting in a change in the potential between the indicator electrode and the reference electrode. Near the equivalent point, the potential between the two electrodes suddenly jumps, and the endpoint of titration can be obtained by combining the sudden potential with the internal calculation program of the instrument. Only by mastering the basic operational knowledge can we avoid errors during use.

1. Remove the pH electrode from a saturated KCl aqueous solution and clean it with distilled water.

2. Insert the pipette into distilled water and the burette into the waste liquid bottle.

3. Turn on the main power and agitator power of the automatic potentiometric titrator, and then start the working program.

4. Click on "Parameters" on the work program interface to set parameters and perform titration settings.

5. Click the "Send" button on the operation page, enter the volume (20-50ml), and then press "Send" to fill the pipeline with liquid.

6. Check for bubbles (if any), insert the bubble needle into the quantitative tube and aspirate the gas.

7. Insert the pipette into the standard solution; Insert the burette into the solution to be tested, then place the pipette on the magnetic stirrer in the solution to be tested, and put down the stirrer. Repeat step 5 above.

8. Insert the cleaned pH electrode into the solution to be tested, i.e. immerse the electrode tip into the liquid.

After the equipotential is basically stable, start the measurement program on the operation interface.

At this point, the instrument draws a curve on the screen during titration. After titration, the instrument will automatically calculate the endpoint volume, endpoint potential, and the concentration of the liquid to be measured.

At the end of the measurement, remove the electrode, clean it, and put it back into KCl saturated liquid for use. Turn off the automatic potentiometric titrator and computer, turn off the power, and then end the operation.