Instruction manual

pH CALIBRATION & MEASUREMENT

General Calibration Procedure

For detailed calibration and temperature compensation procedures,

consult your meter instruction manual.

Two-Buffer Calibration

This procedure is recommended for precise measurement.

1. Ensure that all buffers are at the same temperature. If samples

are at varying temperatures, temperature compensation is

recommended. (See meter instruction manual.)

2. Select two buffers which bracket the expected sample pH. The

first should be near the electrode isopotential point (pH 7) and

the second near the expected sample pH (e.g., pH 4 or 10)

3. Rinse electrode first with distilled water and then with the first

(pH 7) buffer. Place the electrode in the first (pH 7) buffer.

4. Wait for a stable display. Set the meter to the pH value of the

buffer at its measured temperature. (A table of pH values at

various temperatures is supplied on the buffer bottle.) See

Table 1.

5. Rinse electrode first with distilled water and then with the

second buffer. Place the electrode in the second buffer.

6. When the display is stable, set meter to the pH value of the

buffer at its measured temperature as described in the meter

instruction manual.

7. If all steps are performed correctly, proceed to the pH

Measurement section. If any of the above procedures do not

work, see Troubleshooting.