Hanna Instruments HI 9910 User Manual

Page 34

SUGGESTED INSTALLATIONS

for pH/ORP ELECTRODES

The electrode should be installed in such a way that its tip
permanently lies in the solution whether in a well, tank or on the
discharge pipe.

SHORT DISTANCE, INDOOR INSTALLATION

Due to the low currents involved, a very high grade of insulation is
required. A dry environment is needed in order to obtain a level of
insulation not lower than 10

Ω

This type of connection is very delicate and requires constant attention
to maintain proper operating conditions.
The conventional electrodes may be used for indoor applications but
the cable length should not exceed 10 m (33').

TROUBLESHOOTING

Evaluate your electrode performance based on the following.
•

Noise (Readings fluctuate up and down) could be due to a
clogged/dirty junction: Refer to the Cleaning Procedure above.

•

Dry Membrane/Junction: Soak in Storage Solution HI 70300
overnight. Check to make sure the installation is such as to create
a well for the electrode bulb to constantly remain moist.

•

Low Slope: Refer to the cleaning procedure above.

•

No Slope: - Check the electrode for cracks in glass stem or bulb

(replace the electrode if cracks are found).

- Make sure cable and connections are not dam-

aged nor lying in a pool of water or solution.

•

Slow Response/Excessive Drift: Soak the tip in Hanna Solu-
tion

HI 7061 for 30 minutes, rinse thoroughly with distilled

water and then recalibrate the meter.

•

For ORP Electrodes: Polish the metal tip with a lightly abrasive
paper (paying attention not to scratch the surface) and wash
thoroughly with water.

Note: With industrial applications, it is always recommended to keep

at least one spare electrode handy. When anomalies are not
resolved with a simple maintenance, change the electrode
(and recalibrate the controller) to see if the problem is
alleviated.

This manual is related to the following products:

HI 9911 HI 9920