VOLTCRAFT PH-212 Notice D'emploi page 35

The PH-212 has a two-point callibration (7.00 and 4.00/10.0) sys-
tem, can however be adapted only with a single point callibration
(7.00) also. Two-point callibration gives better accurate values. If the
measuring medium is extremely alkaline or extremely acidic, a two-
poing calibration is recommended.
Note for callibration!
It is not necessarily to callibrate the PH-212 before each
measurement. It is recommended to carry out calibration
before every tenth measurement or every two weeks.
Should the supplied buffer/calibration be used up, these
can be bought extra.
Note for pH electrode
The pH electrode must be always be kept wet for obtain-
ing accurate results over a long period. The pH electrode
must be always be stored immersed in the storage solu-
tion. Should the storage liquid be used up, this can be
bought extra.
The pH electrode is a wear and tear part. Worn out elec-
trodes are excluded from the warrantee.
Two-point calibration
- Insert the BNC connection plug (8) of the electrode into the BNC
female connector (4) and lock it by turning through 90°.
- Remove the pH electrode from the storage solution (10), rinse it
well with distilled or de-ionised water and insert it into the provid-
ed 7.00 pH buffer/calibration solution.
- Switch on the pH measuring device by pressing the ON/OFF but-
ton (2).
- Wait until the display is stabilized and bring the pH value dis-
played exactly to 7.00 by turning the "pH7" calibration trimmer
(6) with a small screwdriver.
- Remove the pH electrode from 7.00 pH buffer/calibration solu-
tion, rinse it well with distilled or de-ionised water and insert it into
the provided 4.00 pH buffer/calibration solution.
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- Wait until the display is stabilized and bring the pH value dis-
played exactly to 4.00 by turning the "pH4" calibration trimmer
(7) with a small screwdriver. The second calibration point can also
be performed at pH 10.00, you must however use an appropriate
10 pH buffer/callibration soution (optional).
- Rinse the pH electrode well again with distilled or de-ionised
water and check whether the pH 7-value is still correct, by insert-
ing the electrode into the provided 7.00 pH buffer/calibration
solution. Repeat the calibration processes untill both values are
optimally matched to the buffer/calibration solutions.
Single-point calibration
- Insert the BNC connection plug (8) of the electrode into the BNC
female connector (4) and lock it by turning through 90°.
- Remove the pH electrode from the storage solution (10), rinse it
well with distilled or de-ionised water and insert it into the provid-
ed 7.00 pH buffer/calibration solution.
- Switch on the pH measuring device by pressing the ON/OFF but-
ton (2).
- Wait until the display is stabilized and bring the pH value dis-
played exactly to 7.00 by turning the "pH7" calibration trimmer
(6) with a small screwdriver.
Carrying out measurements
- Remove the pH electrode from the storage solution, rinse it with
distilled or de-ionised water and wipe it dry.
- Immerse the pH electrode into the medium, the pH of which has
to be measured. After the display stabilizes the pH value of the
liquid can be read directly. The automatic temperature compen-
sation (ATC) always provides an accurate value even at different
temperatures. It is however recommended to carry out calibration
for temperatures outside 15 to 35°C.
- In order to ensure a long life-span of the device, the pH electrode
must be cleaned after each measurement (see Maintenance and
Cleaning)
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