7 | Maintenance
PH20
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B-H86.0.11.DB201-1.0
7.3.1.2 Buffer solutions
Description
At least one buffer solution is required to calibrate the product. In the process, you
have the option of using a ready-to-use PHL buffer solution or mixing the solution
yourself with GPH buffer capsules - refer to the instructions.
Colour
10 °C
20 °C
25 °C
30 °C
40 °C
4.0
Red
4.02
4.00
4.01
4.01
4.01
7.0
Green
7.06
7.02
7.00
6.99
6.97
10.0
Blue
10.18
10.07
10.01
9.97
9.89
For ready-to-use buffer solutions, visit www.vwr.com.
Prerequisite
– Plastic bottle
– approx. 100 ml of distilled water
– Buffer capsule
Instruction
1. Fill a plastic bottle with approx. 100 ml of distilled water.
2. Open the buffer capsule carefully by twisting the capsule halves and pulling. It
should be ensured that nothing is spilled. They can also be used without opening
them; opening the capsules only reduces to time for dissolving.
3. Place the buffer capsule and its contents in the plastic bottle.
4. Wait at least 3 hours.
5. Shake well before using for the first time.
Outcome of an action
Then you can begin with calibration of the product.
7.3.1.3 Automatic pH calibration
Description
The following steps describe how to calibrate the product automatically.
Prerequisite
– The product is switched on.
– The pH electrode is inserted in the product.
– Ready-to-use 7.0 buffer solution.
– Ready-to-use 4.0 or 10.0 buffer solution.
NOTE
Automatic calibration can also be carried out with the pre-mixed buffer solutions. Since
the temperature compensation relates to the GPH capsules, an error of a few hun-
dredths pH should be taken into account, depending on the temperature. Refer also to
the differences in the tables of the buffer solutions in Description and --- FEHLENDER
LINK ---.
Instruction
1. Press the
Function key
for 4 seconds to open the
Calibration
menu.
(AL
appears in
the display.
2. Release the
Function key
.
3.
PK 7
appears in the display.
4. Place the electrode in the 7.0 buffer solution.
5. The product determines the correct value automatically. If the value is determined,
the display flashes to indicate a change to the next calibration point.
6. Enter the temperature of the buffer solution by pressing the
Up key
and
Down key
and confirm the entry by pressing the
Function key
again.
7.
PK 4
and
PK 10
alternate in the display.
8. Then, rinse the electrode with distilled or deionised water.
