For better accuracy, frequent calibration of the instru-
ment is recommended. In addition, the instrument
must be recalibrated whenever:
a) The EC/TDS probe is replaced.
b) After testing aggressive chemicals.
c) Where high accuracy is required.
d) At least once a month.
To change the EC/TDS coversion factor
(CONV) and the temperature compensa-
tion coefficient
βββββ
(BETA)
• From measurement mode, press and hold the
/
MODE button until TEMP and the current tempera-
ture unit are displayed on the lower LCD (E.g.
TEMP °C).
• Press the
/MODE button again to show the
current conversion factor (E.g. 0.50 CONV).
• Press the SET/HOLD button to change the conver-
sion factor.
• Press the
/MODE button to show the current
temperature compensation coefficient
β
(E.g. 2.1
BETA).
• Press the SET/HOLD button to change the the
temperature compensation coefficient
β
.
• Press the
/MODE button to return to the normal
measuring mode.
Calibration procedure
• From measurement mode, press and hold the
/
MODE button until CAL is displayed on the lower
LCD.
• Release the button and immerse the probe in the
proper calibration solution:
HI 7031
(1413 µS/cm)
for
HI 98311
and
HI 7030
(12.88 mS/cm) for
HI
98312
.
• Once the calibration has been automatically per-
formed, the LCD will display OK for 1 second and
the meter will return to normal measurement mode.
• Since there is a known relathionship between EC
and TDS readings, it is not necessary to calibrate
the meter in TDS. If the EC/TDS conversion factor is
either 0.5 or 0.7, the meter will allow a direct
calibration in ppm by using the Hanna calibration
solutions listed below.
The CAL symbol on the LCD means that the meter is
calibrated.
To reset to the default calibration
To clear a previous calibration, press the MODE
button after entering the calibration mode. The lower
LCD will display ESC for 1 second and the meter will
return to normal measurement mode. The CAL symbol
on the LCD will disappear. The meter will be reset to
the default calibration.
CALIBRATION
BATTERY REPLACEMENT
PROBE MAINTENANCE
The EC/TDS probe can be easily replaced by using the
supplied tool (
HI 73128
). Insert the tool into the probe
cavity as shown below.
Rotate the probe counterclockwise.
Pull the probe out by using the other side of the tool.
Insert a new probe following the above instructions in
reverse order.
To
turn the meter on and to check battery status
Press and hold the
/MODE button for 2-3 sec-
onds. All the used segments on the LCD will be visible
for a few seconds, followed by a percent indication of
the remaining battery life (E.g. % 100 BATT).
Taking measurements
Submerge the probe in the solution to be tested. Use
plastic beakers to minimize any electromagnetic inter-
ferences.
Select either EC or TDS mode with the SET/HOLD
button.
The measurements should be taken when the stability
symbol on the top left of the LCD disappears.
The EC (or TDS) value automati-
cally compensated for temperature
is shown on the primary LCD
while the secondary LCD shows
the temperature of the sample.
To change the temperature unit
To change the temperature unit (from °C to °F), from
measurement mode, press and hold the
/MODE
button until TEMP and the current temperature unit
are displayed on the lower portion of the LCD (E.g.
TEMP °C).
Use the SET/HOLD button to change the temperature
unit, and then press the
/MODE button twice to
return to the normal measuring mode.
To freeze the display
Press the SET/HOLD button for
2-3 seconds until HOLD appears
on the secondary display.
Press either button to return to
the normal measuring mode.
To turn the meter off
Press the
/MODE button while in normal measur-
ing mode. OFF will appear on the lower part of the
display. Release the button.
Notes
:
• Before taking any measurement make sure the
meter has been calibrated.
• If measurements are taken in different samples
successively, rinse the probe thoroughly to eliminate
cross-contamination; and after cleaning, rinse the
probe with some of the sample to be measured.
OPERATIONAL GUIDE
ACCESSORIES
HI 73311
Replaceable EC/TDS probe
HI 73128
Probe removal tool
HI 70030P
12.88 mS/cm solution, 20 mL sa-
chet (25 pcs)
HI 70031P
1413 µS/cm solution, 20 mL sa-
chet (25 pcs)
HI 70032P
1382 ppm solution, 20 mL sachet
(25 pcs)
HI 70038P
6.44 ppt solution, 20 mL sachet
(25 pcs)
HI 70442P
1500 ppm solution, 20 mL sachet
(25 pcs)
The meter displays the remaining battery percentage
every time it is switched on. When the battery level is
below 5%, the
symbol on the bottom left of the LCD
lights up to indicate a low battery condition. The batter-
ies should be replaced soon. If the battery level is low
enough to cause erroneous readings, the meter shows
“0%” and the Battery Error Prevention System (BEPS) will
automatically turn the meter off.
To change the batteries, remove the 4 screws located on
the top of the meter.
Once the top has been removed, carefully replace the 4
batteries located in the compartment while paying atten-
tion to their polarity.
Replace the top, making sure that the gasket is properly
seated in place, and tighten the screws to ensure a
watertight seal.
