ACCESSORIES
HI 761285
Conductivity probe with built-in temperature sen-
sor, DIN connector and 1 m (3.3’) cable
HI 70032P
1382 ppm solution, 20 mL sachet (25 pcs)
HI 7032M
1382 ppm solution, 230 mL bottle
HI 7032L
1382 ppm solution, 500 mL bottle
HI 70039P
5000 μS/cm solution, 20 mL sachet (25 pcs)
HI 7039M
5000 μS/cm solution, 230 mL bottle
HI 7039L
5000 μS/cm solution, 500 mL bottle
HI 700661P
Cleaning solution, general purpose, 20 mL sa-
chet (25 pcs)
HI 7061M
Cleaning solution, general purpose, 230 mL
HI 7061L
Cleaning solution, general purpose, 500 mL
HI 7073M
Protein cleaning solution, 230 mL bottle
HI 7073L
Protein cleaning solution, 500 mL bottle
HI 7074M
Inorganic cleaning solution, 230 mL bottle
HI 7074L
Inorganic sleaning solution, 500 mL bottle
HI 7077M
Oil & Fat cleaning solution, 230 mL bottle
HI 7077L
Oil & Fat cleaning solution, 500 mL bottle
TAKING MEASUREMENTS
• The meter is supplied complete with a 9V battery. Remove
the battery compartment cover on the back of the meter
and install the battery while paying attention to its
polarity.
• Connect the probe to the DIN socket on the top of the meter
by aligning the pins with the socket and pushing in the
plug.
• Turn the meter on by pressing the ON/OFF key.
• Immerse the tip of the probe into the sample to be tested. If
possible, use plastic beakers to minimize any EMC interference.
• Tap the probe lightly on the bottom of the beaker to
remove any air bubbles which may be trapped inside.
• Select the desired measurement range, by pressing the
corresponding key: “μS/cm” for EC or “ppm” for TDS.
• Wait a couple of minutes for the temperature sensor to
reach thermal equilibrium. The display will then show the
measurement automatically temperature compensated for
temperature with the appropriate indication: “μS”
symbol
indicates the meter is in EC mode, while no symbol means
that the meter is in TDS mode.
• To read the temperature of the solution, select the tem-
perature mode, by pressing the “°C” key.
• Wait a couple of minutes for the
reading to adjust and stabilize.
The display will show the tem-
perature value.
Note:
If the display shows only “E”
on the right hand side, the
reading is out of range.
Note:
It is recommended to clean often the probe (see “Probe
Maintenance” section for details).
Note:
After measurements, switch the meter off, clean the
probe and store it with the protective cap.
PROBE MAINTENANCE
Periodic Maintenance
• Inspect the probe and the cable. The cable used for the
connection to the meter must be intact and there must be
no points of broken insulation on the cable or cracks on the
probe stem or bulb.
• Connector must be perfectly clean and dry. If any scratches
or cracks are present, replace the electrode. Rinse off any
salt deposits with water.
Cleaning Procedure
For better accuracy in measurements and to ensure a good
performance of the probe, a frequent cleaning is recommended.
• Immerse the tip of the probe in the
HI 7061
cleaning
solution for half an hour.
Note
: For particular dirty (as for example protein, oil or
grease), see the “Accessories” section for Hanna specific
solutions.
• If a more thorough cleaning is required, brush the metal
pins with very fine sandpaper.
• After cleaning, rinse the probe with tap water and recalibrate
the instrument. If it is not possible to calibrate, the probe
has to be replaced with a new one.
Note:
For field applications, it is always recommended to keep
a spare probe handy. When anomalies are not resolved
with simple maintenance, change the probe and
recalibrate the meter.
CALIBRATION
• Turn the meter on.
• Pour a small quantity of
HI 70039
(5000 μS/cm) EC
calibration solution or
HI 70032
(1382 ppm) TDS calibra-
tion solution into a clean beaker. If possible, use plastic
beakers to minimize any EMC interference.
Note:
The conversion factor between EC and TDS readings is
made by a built-in circuit. Therefore, it is requested to
calibrate only one range (EC or TDS), and the other
range will be automatically calibrated.
• Immerse the probe in the calibration solution and wait for
a couple of minutes for thermal equilibrium to be reached.
• Tap the probe on the bottom, then shake it, to make sure
no air bubbles remain trapped inside the probe.
• Press the "μS/cm" (or "ppm") key.
• Turn the EC/TDS calibration knob un-
til the display shows the calibration
solution value.
Note:
For best accuracy, the probe body should not touch nor
stand close to the side walls of the beaker.
CE DECLARATION OF CONFORMITY
IST8731 04/05
EC/TDS CONVERSION FACTOR
The TDS value in aqueous solutions is directly proportional to
the conductivity. The ratio between the two parameters de-
pends on the solution.
HI 8731
is provided with a fixed conversion factor, set to 0.5.
This means that 1 μS/cm is equal to 0.5 ppm of TDS.
BATTERY REPLACEMENT
This meter is powered by a 9V alkaline battery.
A low battery condition is indicated
by a blinking additional decimal
point. When the low battery indica-
tion appears, only a few hours of working time are left.
When the battery level is too low to ensure reliable measure-
ments, the meter turns off.
It is recommended to replace the battery immediately.
Battery replacement must only take
place in a nonhazardous area us-
ing a 9V alkaline battery.
Unscrew the three screws on the
rear of the meter, remove the bat-
tery compartment cover and replace
the 9V battery with a new one,
while paying attention to the cor-
rect polarity.
Make sure the battery contacts are tight and secure before
replacing the cover.
