Sera PRECISION pH meter Manual De Instrucciones página 8

4. Turn the "pH7 adjustment knob" (1.4) until the dis-
play reads exactly 7.00.
5. Carefully rinse the electrode with distilled water.
6. Immerse the electrode in the pH 4.00 test solution
(6). Turn the "pH4 adjustment knob" (1.3) until the
display reads exactly 4.00. Rinse the electrode with
sera aqua-dest.
7. Repeat this procedure once, beginning with step 2.
8. The test solutions or the pH electrode should be
replaced if the test solutions reveal a deviation of
more than 0.15 pH units after two calibration runs.
Measuring process
The unit is now ready to measure after the meter and
the pH electrode have been calibrated.
1. Switch on the unit.
2. Immerse the pH electrode into the solution to be
measured up to the marking.
3. The display will have stabilized after about ten to
twenty seconds, allowing to read off the displayed
measured value.
4. Rinse the electrode with distilled water after you
have carried out the measurement and store it in
the protection cap filled with 3 mol/l KCl care solu-
tion.
5. Switch off the meter after use.
Cleaning the casing
The meter must be switched off when it is cleaned.
Please clean the casing with a dry cloth, not a moist
one.
Maintenance
It is better to calibrate the pH in intervals of 2 – 4 weeks
as to ensure the measurement readings remain pre-
cise for a long time.
Electrode
The pH electrode should be cleaned if achieving a sta-
ble pH value in the display takes longer than a minute.
Fill 10 ml (0.34 fl.oz.) sera cleaning solution into a meas-
urement vial to do so and clean the pH-electrode in
there for 10 minutes. Then rinse the electrode thor-
oughly and regenerate it in KCl care solution for
12 hours. The electrode must be replaced if the meter
cannot be calibrated any more (see two point calibra-
tion).
The KCl care solution in the protection cap (8) for stor-
ing the electrode should be replaced with new solu-
tion every six months.
Technical Data
Display:
Measuring range:
Step width:
Measurement precision: ±0.1 pH units
Input resistance:
Reaction time:
Ambient temperature:
Surrounding humidity:
Calibration screw:
Supply voltage:
Energy consumption:
Dimensions:
Weight:
IMPORTANT INFORMATION!
Do not carry out measurements with the sera pH me-
ter while treating fish diseases or while treating algae
(electrode contamination!).
A contaminated electrode cannot be regenerated and
is also not covered by warranty.
If the display does not remain stable after a certain
time, but drifts slowly into one direction, the electrode
is dirty and needs cleaning. Immerse the tip of the pH
electrode in the sera cleaning solution for 10 – 15 min-
utes. You must never clean the electrode mechanical-
ly! After cleaning, soak the pH electrode for 12 hours,
then rinse with distilled water and recalibrate (section
"calibration of the pH electrode").
Please be sure to always push the protection cap on
the electrode immediately after use. One minute air
contact is often sufficient to let the electrode become
dry, leading to faulty measurements.
In such cases, soak the pH electrode for 12 hours, then
recalibrate.
Immersion depth of electrodes:
too high
correct
This unit is not suitable for other application ranges,
especially with extreme pH values and dangerous
organic and/or inorganic contamination.
8
18 mm (0.7 in.)
LCD 3 1 / digits
2
0 – 14 pH
0.01 pH
after calibration
12
10 Ohm
0.4 seconds
0 – 50°C (32 – 122°F)
less than 90% RH
pH 4 and pH 7 (calibration)
battery 006P DC9V
approx. 2 mA DC
170 x 80 x 34 mm
(6.7 x 3.2 x 1.3 in.)
approx. 210 g (0.5 lb.)
correct
too low