Hanna Instruments HI 8731 User manual

Instruction Manual
HI 8731
Portable
EC, TDS, Temperature
Meter
www.hannainst.com
WARRANTY
This instrument is guaranteed for two years against
defects in workmanship and materials when used for their
intended purpose and maintained according to instructions.
Electrodes and probes are guaranteed for six months.
This warranty is limited to repair or replacement free of charge.
Damages due to accidents, misuse, tampering or lack of
prescribed maintenance are not covered. If service is required,
contact the dealer from whom you purchased the instrument. If
under warranty, report the model number, date of purchase,
serial number and the nature of the failure. If the repair is not
covered by the warranty, you will be notified of the charges
incurred. If the instrument is to be returned to Hanna
Instruments, first obtain a Returned Goods Authorization Num-
ber from the Customer Service department and then send it
with shipment costs prepaid. When shipping any instrument,
make sure it is properly packaged for complete protection.
Dear Customer,
Thank you for choosing a Hanna product.
Please read carefully this instruction manual before using the
meter. If you need additional technical information, do not
hesitate to e-mail us at [email protected].
This instrument is in compliance with the directives.
PRELIMINARY EXAMINATION
Remove the instrument from the packing material and examine
it carefully. If any damage has occurred during shipment,
immediately notify your Dealer or the nearest Hanna Customer
Service Center.
The meter is supplied with:
•HI 761285 conductivity probe with built-in temperature
sensor, DIN connector and 1 m (3.3’) cable
•HI 70039 (5000 μS/cm) calibration solution sachet
•HI 70032 (1382 ppm) calibration solution sachet
• Battery & instructions
Note: Conserve all packing material until the instrument has
been observed to function correctly. Any defective item
must be returned in its original packing.
GENERAL DESCRIPTION
HI 8731 is a complete, versatile and water-tight conductivity
meter, that can measure EC and TDS with extended ranges
(from 0 to 6000 μS/cm range and from 0 to 3000 ppm,
respectively), and temperature from 0 to 70°C.
The desired measurement mode is easily selectable through a
membrane keyboard on the front panel.
Conductivity measurements are automatically compensated for
temperature changes with a fixed coefficient of 2%/°C.
The HI 761285 probe features a built-in temperature sensor,
and it has been designed to require little maintenance.
The meter can be calibrated at one point for EC or TDS, while
the temperature range is factory calibrated.
Recommendations for Users
Before using these products, make sure that they are entirely suitable for the environment in
which it is used. Operation of these instruments in residential areas could cause unacceptable
interferences to radio and TV equipment. Any variation introduced by the user to the supplied
equipment may degrade the instruments’ EMC performance. To avoid electrical shock, do not
use this instrument when voltage at the measurement surface exceeds 24 Vac or 60 Vdc. To
avoid damage or burns, do not perform any measurement in microwave ovens.
FUNCTIONAL DESCRIPTION SPECIFICATIONS
Range EC 0 to 6000 μS/cm
TDS 0 to 3000 ppm
Temperature 0.0 to 70.0°C (*)
Resolution EC 10 μS/cm
TDS 10 ppm
Temperature 0.1°C
Accuracy EC/TDS ±2% f.s.
Temperature ±0.5°C
TDS Factor 0.5
Calibration EC/TDS Manual, 1 point, through front knob
Temperature Factory calibrated
Probe HI 761285 (included)
Temperature Automatic, 0 to 50°C (32 to 122°F)
Compensation with β=2%/°C
Environment 0 to 50 °C (32 to 122°F); RH max 100%
Battery Type / Life 1x9V alkaline / approx. 250 hours
Dimensions 164 x 76 x 45 mm (6.4 x 3.0 x 1.8’’)
Weight 250 g (8.8 oz.)
(*) If using HI 761285 probe, it is recommended to not exceed 50°C
Hanna Instruments reserves the right to modify the design,
construction and appearance of its products without advance notice.
All rights are reserved. Reproduction in whole or in part is prohibited
without the written consent of the copyright owner, Hanna Instruments.
1) DIN connector for probe
2) Liquid Crystal Display
3) μS/cm (EC) range selection key
4) EC/TDS calibration knob
5) ppm (TDS) selection key
6) °C (Temperature) selection key
7) ON/OFF key

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.