18
Water Action Volunteers – Level 2 Manual
Updated January 2016
Cal. procedure - pH 5 meter with updated software, but original outside casing
The updated software version in the pH 5 allows for you to complete a two-point calibration
without ever leaving the calibration mode. After you press ENTER following the first calibration,
the value on the screen will continue to blink, indicating that it is still in calibration mode (unlike
the old version that stopped blinking after you hit ENTER and went into measuring mode).
1. Connect the pH and temperature probes to meter.
a. Ensure that the pH probe connecter snaps into place.
2. Turn the meter on by pushing the On/Off button on the face of the meter.
3. Record the
date
,
time
, and the
name of analyst
performing the calibration on the calibration log.
4. Remove the pH electrode from the electrode soaker
bottle.
5. Rinse the pH electrode with distilled water and shake the excess water off of the
electrode.
6. Click the MODE button to find the
temperature
reading and
record value
on the calibration log.
7. Click the MODE button again to return to the pH screen on the meter.
8. Press the CAL button on the meter in order to start the calibration process.
9. Place the electrode and temperature sensors into the pH 7 buffer solution
and
submerge the glass bulb completely in the solution.
10. Wait for the reading to stabilize and record the
Stabilized pH
value
on the calibration log.
11. Press the ENTER key once and record the
Calibrated
pH
value
12. Check that the
Calibrated pH
value is within 0.2 of the pH 7 buffer standard.
a. If the value is more than 0.2 higher or lower than its pH buffer value (compare
values in the grey columns, outlined in blue
), recalibrate the meter.
b. Record the new results on the next line of the pH meter calibration log.
13. Remove the electrode from the pH 7 buffer solution, rinse with distilled water and
shake off the excess water from the electrode.
14. Place the electrode and temperature sensors directly into the pH 10 buffer solution
and
submerge the glass bulb completely in the solution
