Sera PRECISION pH meter Manual De Instrucciones página 7

US
Information for use
Please read these instructions carefully and keep for future use.
Application range
The digital sera pH meter was specially developed for
aquarium purposes. Fresh and salt water aquariums,
pond water, natural surface water and tap water are
the application fields.
Contents
1. sera pH meter
2. sera pH measuring electrode
3. Universal holder for pH electrode
4. Adjustment tool
5. Battery 9 V (006P DC9V)
6. sera test solution pH 4.0
7. sera test solution pH 7.0
Starting up
Description of the front side
1.1 Display
1.2 On/off switch
1.3 pH4 adjustment knob
1.4 pH7 adjustment knob
1.5 BNC port for pH electrode
1.6 Battery level display (BAT)
Connecting the pH electrode
Push the BNC plug of the electrode into the BNC sock-
et of the meter (1.5). The BNC connection will lock by
twisting slightly. The electrode is now connected.
Inserting and changing the battery
Remove the battery cover on the back side, insert bat-
tery and close the cover.
The word "BAT" appearing on the left side of the LCD
display means a battery voltage of less than 6.5 – 7.5 V.
The battery must be replaced.
Take the battery out and insert a new one (006P DC9V).
Calibration process
Calibration reason
This pH meter is already calibrated with a mV signal
simulating the value of an ideal electrode (based on a
surrounding temperature of 25°C [77°F]). An ideal elec-
trode will display 0 mV at pH 7.00. However, most elec-
trodes will slightly deviate, and the surrounding tem-
perature is not necessarily at 25°C (77°F). It is therefore
necessary to carry out the following calibration pro-
cess as to obtain precise measurements from the
meter along with the electrode.
Required accessories for calibration
- pH electrode with BNC connector (2) item No. 08921
- sera test solution pH 7.0 (7) item No. 08923
- sera test solution pH 4.0 (6) item No. 08916
- thermometer (not included)
- sera aqua-dest (not included)
- sera care solution KCl item No. 08931 (not included)
- sera cleaning solution item No. 08930 (not included)
Keep in mind that only the electrode shaft is made of
plastic. The inner capillary tubes, however, are made of
glass and very fragile.
Carefully remove the electrode protection cap from
the electrode tip first. A white salt-like deposit may
coat the electrode tip. This is normal and dissolves
after a few minutes in the water. Then place the elec-
trode tip in a clean glass filled with tap water for
12 hours. Please note the correct immersion depth
(see illustration and electrode marking).
Calibration of the pH electrode
The next step is to calibrate the pH electrode using the
test solutions pH 4.0 and 7.0 (6/7). Please use a meas-
urement vial (10 ml) as to keep test solution consump-
tion as low as possible. Do not use a used test solution
again. Please close the opened 100 ml (3.38 fl.oz.) bot-
tle immediately again.
Safety color indicators of the sera test solutions
Caution: The sera test solutions contain color indica-
tors. The sera test solution pH 4.0 is red, the sera test
solution pH 7.0 is green. Test solutions that are dirty or
too old change or lose these colors. Using such test
solutions can lead to dangerous measuring errors!
Note: Not all impurities cause color destruction or
color change. Therefore it is especially important to
treat the test solutions carefully. Never use test solu-
tions more than once or fill them back into the bottle!
We recommend storing opened test solutions for a
maximum of 12 months at room temperature, even if
the color indicators are still intact.
Two point calibration
1. The electrode must be soaked for 12 hours in an
open glass filled with clean, chlorine-free water be-
fore use. Tap water is often chlorinated and may
damage the electrode. Allow chlorinated water to
stand in an open glass at least for 24 hours before
using it.
Electrodes damaged by chlorinated water are not
covered by warranty.
First take off the electrode protection cap as fol-
lows:
• place the electrode in an upright position
• unscrew the plastic cap counterclockwise from
the bottle by hand
• the pH electrode can now easily be pulled out of
the protection container while the cap with the O-
ring seal remains on the electrode
2. Connect the BNC plug of the electrode to the ac-
cording socket on the meter (1.5). Immerse the elec-
trode in the pH 7.00 test solution (7). Wait for 30 sec-
onds.
Close the test solution 7.0 with the screw cap as to
effectively prevent wrong measuring results caused
by swapped caps.
3. Switch on the meter (1.2) and wait until the dis-
played measured value has stabilized. This may take
up to half a minute with new electrodes, and up to
2 minutes with older electrodes.
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