Nova-Tech pH-CON 300 - Manual (Page 22)

43 42
8. Troubleshooting
Problem Cause Solution
Power on but a) Batteries not in place. a) Check that batteries are in
no display place and making good
contact.
b) Batteries not in correct b) Reinsert batteries with
polarity (+ and –). correct polarity.
c) Weak batteries. c) Replace batteries.
Not responding a) HOLD mode in operation. a) Cancel HOLD mode.
to key press
b) Damaged key pad. b) Return to dealer.
c) Internal program error. c) Reset all internal programs
by reinserting batteries.
Unstable a) Air bubbles in probe. a) Tap probe to remove bubbles.
readings
b) Dirty probe. b) Clean the probe and
recalibrate.
c) Probe not deep c) Make sure sample entirely
enough in sample. covers the probe sensor(s).
d) External noise pickup d) Move or switch off
or induction caused by interfering motor.
nearby electric motor.
e) Broken probe. e) Replace probe. See page 46.
“OR” on upper a) Probe is shorted. a) Test probe. Make sure probe
display is fully connected to meter.
b) Probe is in an b) Use different solution.
out-of range solution.
c) Broken probe. c) Replace probe. See page46.
Temperature reading a) Temperature of solution a) Heat or cool solution.
erratic or lower is out of range
display reads “OR”
Slow response a) Dirty/Oily probe. a) Clean probe. See "Probe
Care & Maintenance",
pages 41-42.
pH electrode activation (for glass bodied electrodes only)
WARNING: Only qualified persons proficient with the safe handling of dangerous
chemicals should perform the procedure below. Provide proper containers, fume
hoods, ventilation, and waste disposal. Safety goggles and protective clothing must
be worn while performing this procedure. If possible, replace with another electrode
instead of performing this reactivation procedure.
1. Dip or stir the pH electrode in alcohol for 5 minutes.
2. Leave the electrode in tap water for 15 minutes.
3. Dip and stir the electrode in concentrate acid (such as HCl or H
2
SO
4
) for 5 minutes.
4. Repeat step 2.
5. Dip and stir in strong base (NaOH) for five minutes.
6. Leave for 15 minutes in distilled or deionized water.
7. Now test with standard calibration buffer solutions to see if the electrode yields
acceptable results. You may repeat step 3 through 6 up to three times for better
response. If the response does not improve, then your electrode is no longer
functioning. Replace with a new electrode—call your OAKTON Distributor for more
information.
Conductivity/TDS probe care
Keep the conductivity/TDS probe clean. Rinse the probe
twice, and gently swirl it while you take readings. For
best accuracy, soak a dry probe for at least 5 to 10 min-
utes or longer before calibration. Rinse the probe with
deionized or tap water before storing. Never scratch the
platinum portions with a hard substance. Do not strike
the probe against any hard surface.
Do not make continuous contact with your solutions.
Readings will rise over a
period of time while you soak your probe.
Do not immerse the probe in oily solutions. Clean the
electrode thoroughly by stirring it in a mild detergent
bath or isopropyl alcohol. Wipe the probe with a soft tis-
sue paper. Rinse thoroughly in tap water and then in
deionized water. Recalibrate the meter after cleaning the
probe.
The conductivity/TDS probe included with your meter
features a removable probe guard to make cleaning easy.
To remove probe guard:
1. Grip yellow probe guard and twist
clockwise. The locking notch will release.
2. Slide probe guard off end of probe.
locking
notch
twist probe
guard
clockwise
to remove
Probe model
WD-35608-50
7.2
http://www.novatech-usa.com/Products/Laboratory-Equipment-Supply-Products Tel: (281) 359-8538 Toll Free:(866) 433-6682