Trotec BW10 Instructions Manual page 6

3. Screw the lid back on the battery compartment. In doing
so, make sure that the rubber seal is properly seated.
Removing the protective cap
The device has already been calibrated at the factory using a
highly concentrated saline solution. This often leads to the
formation of salt crystals at the diaphragm electrode (fibre
bundle) during later usage. These visible residues are
completely normal for pH measuring electrodes of this type.
Such residues are harmless for the measuring electrode and
can easily be washed off with water; thus they do not represent
any quality defect!
The measuring electrode is protected from external influences
by means of a protective cap (9).
1. Prior to every measurement pull the protective cap off the
measuring electrode (8).
2. After every measurement put the protective cap back on
the electrode.
6
1
BW 10
CAL
HOLD
8
9
Switching the device on
1. Press the Power (5) button to switch the device on.
Performing a calibration
Info
Before calibration immerse the measuring probe (7) in
distilled water for approx. 10 to 15 min.
To perform a calibration of the pH measuring device, you first
have to prepare the buffer solutions contained in the supplied
set.
The buffer solutions correspond to the pH values 4 (red),
7 (green) and 10 (blue) with an accuracy of ±0.01 pH (at 25 °C).
Please proceed as follows to prepare a buffer solution:
Caution
The powder for the buffer solutions as well as the
buffer solutions made thereof are unfit for human
consumption.
Caution
Sodium carbonate (Na
solution 10.01) may cause eye irritation. Upon contact
with eyes, thoroughly rinse with water and seek
medical advice.
Keep sodium carbonate out of the reach of children.
Do not breathe dust containing sodium carbonate.
1. Fill the contents of a sachet (e.g. pH 7 = green) into a
beaker glass or suitable glass vessel with a capacity of at
least 250 ml.
2. Add 250 ml of distilled water.
3. Stir the solution with a glass rob until the powder is
completely dissolved.
Please note that the pH value of the buffer solution may vary
depending on the temperature. The table below indicates the pH
value as a function of the temperature (see also imprint on
plastic sachets):
°C pH 4
10 4.00
15 4.00
20 4.00
25 4.00
30 4.01
35 4.02
40 4.03
45 4.04
50 4.06
pH measuring device BW10
CO , contained in buffer
2 3
pH 7 pH 10
7.06 10.18
7.04 10.12
7.02 10.06
7.00 10.01
6.99 9.97
6.98 9.93
6.97 9.89
6.97 9.86
6.96 9.83
EN