Sper Scientific 850055 pH Meter - Advanced - Manual (Page 18)

18
PH PROBE CALIBRATION
Calibrate routinely before use, if the readings seem erratic,
and whenever the batteries are replaced. For the highest
accuracy, we recommend a two point calibration. If only
calibrating at a single point, make certain that the buffer
value is close to the sample that will be measured and the
buffer temperature remains stable.
1. Press POWER to turn the meter on and press MODE to
select “pH” mode. “pH” appears on the LCD.
2. Select the calibration buffer type: NIST or CUSTOM
(see page 14).
Note…
pH 4 may be calibrated using either the NIST
(recommended option) or CUSTOM buffer. pH 7 and pH 10
require the CUSTOM buffer. (See SETUP MODE on page
14.)
3. Rinse the probe in de-ionized water or rinse solution.
DO NOT wipe the pH probe dry. Wiping the probe may
cause static and cause calibration and measurement
instability.
4. Select the pH buffer and pour enough solution to totally
immerse the probe tip into a clean container.
5. Dip the probe into the container, immersing the probe
tip.
6. Stir the probe gently to create a uniform sample.
7. Press CAL to enter calibration mode. “CA” will flash on
the LCD. The pH value appears on the main display and
2.00 appears on the secondary display (CUSTOM) or
4.00 appears on the secondary display (NIST).