Hanna Instruments HI 720 User manual

Instruction Manual
HI 720
Conductivity
Process Controller
with Inductive Probe

3
TABLE OF CONTENTS
WARRANTY ......................................................................................................4
PRELIMINARY EXAMINATION.............................................................................5
MODEL IDENTIFICATION..................................................................................5
GENERAL DESCRIPTION & THEORY OF OPERATION .........................................6
SPECIFICATIONS .............................................................................................9
FUNCTIONAL DESCRIPTION...........................................................................10
INSTALLATION................................................................................................12
OPERATIONAL GUIDE ....................................................................................14
• SETUP MODE ...........................................................................................14
• CALIBRATION MODE................................................................................34
• CONTROL MODE ....................................................................................37
• IDLE MODE..............................................................................................43
• LAST CALIBRATION DATA VIEWING MODE ................................................43
• DIAGNOSTIC MODE................................................................................44
TEMPERATURE COMPENSATION.....................................................................46
CONCENTRATION CURVES............................................................................48
HOLD MODE .................................................................................................50
IN-LINE CLEANING.........................................................................................52
COMMUNICATION........................................................................................54
• PC COMMUNICATION.............................................................................54
• SHORT MESSAGING SERVICE (SMS)..........................................................67
• MODEM CONNECTION ..........................................................................71
ERRORS - FAULT CONDITIONS .......................................................................73
ALARM - ERROR CONFIGURATION.................................................................74
SELFTEST PROCEDURES..................................................................................77
ACCESSORIES ................................................................................................80

4
WARRANTY
All Hanna Instruments meters are guaranteed for two years (sensors,
electrodes and probes for six months) against defects in workmanship and
materials when used for their intended purpose and maintained according to
instructions.
This warranty is limited to repair or replacement free of charge. Damage due to
accident, 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 number from the Customer Service department and then
send it with shipping costs prepaid.
When shipping any instrument, make sure it is properly packaged for complete
protection.
Dear Customer,
Thank you for choosing a Hanna Instruments product. Please read this instruction
manual carefully before using the controller. For more information about
Hanna Instruments and our products, visit www.hannainst.com or e-mail us at
[email protected].
For technical support, contact your local Hanna Instruments Office or e-mail us
at [email protected].
Hanna Instruments reserves the right to modify the design,
construction or 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 Inc., Woonsocket,
Rhode Island, 02895, USA.

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PRELIMINARY EXAMINATION
Remove the instrument from the packing material and examine it carefully to
make sure that no damage has occurred during shipping. If there is any notice-
able damage, notify your Dealer or the nearest Hanna Customer Service Center
immediately.
Note Save all packing materials until you are sure that the instrument func-
tions correctly. Any damaged or defective items must be returned in
their original packing materials together with the supplied accessories.
MODEL IDENTIFICATION
The models HI 720 XYZ-αare conductivity controllers.
The meaning of the last letters is according to the following scheme:

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GENERAL DESCRIPTION & THEORY OF OPERATION
This instrument allows conductivity measurements without any electrical contact
between electrodes and process fluid.
The measurement is based on inductive coupling of two toroidal transformers
by the liquid.
The instrument supplies a high frequency, reference voltage to the “Drive Coil”,
and a strong magnetic field is generated in the toroid.
The liquid passes through the hole in the toroid and can be considered as one-turn
secondary winding. The magnetic field induces a voltage in this liquid winding, the
current induced in the flow is proportional to this voltage, and the conductance
of the liquid one-turn winding is according to the Ohm’s law.
The conductance is proportional to the specific conductivity and a constant factor
determined by the sensor geometry and installation.
The liquid also passes through the second toroid and therefore the liquid turn
can be considered as a primary winding of the second toroidal transformer. The
current in the liquid will create a magnetic field in the second toroid, and the
induced current can be measured as an output.
The output current of this “Receive Coil” is therefore proportional to the specific
conductivity of process liquid.

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For an inductive cell, the cell constant is defined as the measured conductivity,
obtained by making a loop through the sensor with a resistor R, multiplied by
that R value.
The cell constant depends only on the sensor geometry. However, when the probe
is immersed in a liquid, the induced current in the solution is affected by the piping
or any other container where the probe is inserted. This effect is negligible when
there is an area of at list 3 cm of liquid around the cell.
Otherwise, it is necessary to multiply measurements by the installation factor:
Conductivity = (cell constant)(installation factor)/(measured resistance)
The installation factor is < 1 for conductive piping/containers, and > 1 for
non-conductive piping/containers.
Since this type of sensor has no electrodes, common problems due to the electrode
contact, such as polarization and contamination, will not affect the performance
of our electrodeless sensor.
The probe working life is extremely long and the sensor maintenance will be an
exceptional operation.
The controllers are equipped with a graphic display, easy to understand as your
cellular phone. Simple messages guide the users through all operations and
parameter setting.

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The main features of the HI 720 controller series include:
• Measurement and control of conductivity or concentration
• Concentration can be measured as usual TDS (fixed ratio) or through custom
conductivity/temperature/concentration curves
• Customizing temperature coefficient table and NaCl temperature compensation
according to IEC 746-3, in addition to the standard linear compensation
• Auto-ranging
• Display reading offset adjustment for temperature
• Temperature level alarm
• Cleaning in place activated through two cleaning commands, or triggered by
a variety of events
• Hold management, including a digital input to enter the hold mode through
an external trigger
• Digital transmitter input
• Pt100 or Pt1000 temperature sensor with automatic recognition and damage test
• Calibration time-out
• Logging of the last 100 error, configuration and cleaning events
• Alarm fault current (3.6 mA or 22 mA)
• SMS messages sending
• Alarm configuration can be customized: different errors can lead different
actions (alarm relay activation, fault current, hold mode, automatic cleaning,
SMS message)
• RS485 communication with additional capabilities, such as error log file down-
loading and cleaning commands
• Daily programmable control timing
• Diagnostic features
• Password protection

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SPECIFICATIONS
Range 0 to 2000 mS/cm (auto-ranging)
-30 to 130°C / -22 to 266°F
Resolution 1 µS/cm (0 to 1999 µS/cm)
0.01 mS/cm (2.00 to 19.99 mS/cm)
0.1 mS/cm (20.0 to 199.9 mS/cm)
1 mS/cm (200 to 2000 mS/cm)
0.1°C / 0.2°F
Accuracy ±2% f.s. (conductivity) / ±0.5°C / ±1°F
Temp. Compensation Automatic or manual, -30 to 130°C
Temperature Probe 3-wire or 2-wire Pt100 or Pt1000 sensor
with automatic recognition and damage test
Digital Input Digital Transmitter, Hold & Advanced Cleaning inputs
Digital Output 1 digital insulated contact closed upon Hold mode
Analog Output 1 or 2 independent outputs;
0-22 mA (configuring as 0-20 mA or 4-20 mA)
Digital Serial Output RS485
Dosing Relay 1, 2, 3 or 4 electromechanical relays SPDT;
5A-250 Vac, 5A-30 Vdc (resistive load);
fuse protected: 5A, 250 V fuse
Alarm Relay 1 electromechanical relay SPDT;
5A-250 Vac, 5A-30 Vdc (resistive load);
fuse protected: 5A, 250 V fuse
Installation Category II
Power Supply 24 Vdc/ac, or
115 Vac or 230 Vac or 100 Vac ±10%, 50/60 Hz;
fuse protected: 400 mA, 250 V fast fuse
Power Consumption 10 VA
Max Oscillation Frequency 8 MHz
Environment 0 to 50°C (32 to 122°F); RH max 85% non-condensing
Enclosure Single case 1/2 DIN
Weight Approx. 1.6 kg (3.5 lb.)

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FUNCTIONAL DESCRIPTION
1. Graphic display (128 x 64 dots)
2. DIAG key, to enter/exit diagnostic mode; to change the conductivity or
concentration range while in setup or calibration mode
3. SETUP key, to enter/exit setup mode
4. CAL DATA key, to enter/exit last calibration data viewing mode
5. CAL key, to enter/exit calibration mode
6. key, to increase current digit by 1, shift to next option, or move to next
record while in diagnostic mode
7. key, to decrease current digit by 1, shift to previous option, or move to
previous record while in diagnostic mode
8. key, to cyclically change temperature compensation option for conductivity
readings: compensation enabled (temperature is continuously displayed) or
compensation disabled (actual reading). Only displayed values are affected
by this key; control and logging are not affected.
9. CFM key, to confirm current choice
10. Contact LEDs, each turns on when the corresponding relay is energized
11. Status (red) and alarm (green) LEDs