Hanna Instruments HI 2400 User manual

1
0
Instruction Manual
HI 2400
Microprocessor
Dissolved Oxygen
Bench Meter
ppm
HI2400
Logging DO Meter
Functions
SETUP
LOG
RANGE
CFM
CAL
Confirm Value
CFM
Change Value
/
Select Logging
LOG
View / Setup Parameters
SETUP
Start DO Calibration
CAL
Select DO Measurement
RANGE
www.hannainst.com

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WARRANTY
HI 2400 is guaranteed for two years against defects in workmanship and
materials when used for their intended purpose and maintained according to
instructions. The electrodes and the probes are guaranteed for a period of six
months. 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 problem. 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 Authori-
zation number from the Technical 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 instrument.
This manual will provide you with the necessary information for correct use of
the instrument, as well as a precise idea of its versatility.
If you need additional technical information, do not hesitate to e-mail us at
[email protected] or turn to the back cover for our worldwide contact list.
This instrument is in compliance with directives.
TABLE OF CONTENTS
PRELIMINARY EXAMINATION ........................................................................................... 3
GENERAL DESCRIPTION.................................................................................................... 3
PROBEFUNCTIONALDESCRIPTION...................................................................................4
HI2400 FUNCTIONAL DESCRIPTION ................................................................................ 5
HI2400SPECIFICATIONS.................................................................................................6
OPERATIONALGUIDE ....................................................................................................... 7
D.O.CALIBRATION.................................................................................................................10
TEMPERATURE CALIBRATION (for technical personnel only) ............................................ 12
SETUP.................................................................................................................................13
LOGGING.............................................................................................................................18
PCINTERFACE....................................................................................................................20
PROBE&MEMBRANEMAINTENANCE..............................................................................25
ACCESSORIES......................................................................................................................26

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PRELIMINARY EXAMINATION
HI2400 is a logging microprocessor-based DO/Temperature bench meter.
It can store up to 99 lots in memory, with up to 8000 readings. These readings
can be transferred to a computer for elaboration or permanent storage.
Dissolved Oxygen is indicated in ppm (parts per million) or in %.
All measurements are automatically compensated for temperature. Salinity
compensation in water allows direct determination of Dissolved Oxygen in saline
waters and altitude compensation readjusts for the altitude variance.
The Dissolved Oxygen probe has a membrane covering the polarographic sensors
and a built-in thermistor for temperature measurements and compensation.
This permeable Teflon®membrane isolates the sensor elements from the
testing solution, but allows Oxygen to pass through. When a voltage is
applied across the sensor, oxygen that has passed through the membrane
reacts causing a current flow, and hence determining a reading.
Remove the instrument from the packing material and examine it carefully to
make sure that no damage has occured during shiping. If there is any
damage, notify your Dealer or the nearest Hanna Customer Service Center.
Each instrument is supplied with:
•HI 76407/2 D.O. probe with 2 m (6.7') cable
•HI 76407A membrane cap (2 pcs)
•HI 7041S electrolyte solution (30 ml)
•12 VDC power adapter
•Instruction Manual
Note: Save all packing material until you are sure that the instrument
functions correctly. All defective items must be returned in their original
packing with the supplied accessories.
GENERAL DESCRIPTION
Teflon®is registered Trademark of “Du Pont de Nemours & Co.”

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PROBE FUNCTIONAL DESCRIPTION
1. D.O. Probe
2. Protective Cap
3. Watertight Shielded Cable
4. Polypropylene Probe Body
5. Temperature Sensor
6. O-Ring Seal
7. Silver Chloride Anode
8. Platinum Cathode (sensor)
9. Oxygen Permeable Teflon®Membrane
10. Membrane Cap
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8
10
9
3
4
1
2
4
5
6

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HI 2400 FUNCTIONAL DESCRIPTION
1) Liquid Crystal Display (LCD).
2) CAL key, to enter/exit calibration mode.
3) CFM key, to confirm different values.
4) key, to select the calibration value or to decrease other parameters.
5) key, to select the calibration value or to increase other parameters.
6) SETUP key, to enter/exit SETUP mode.
7) LOG key, to store measured data.
8) RANGE key, to select the measurement unit or to switch the focused data.
9) ON/OFF switch.
10) Power supply socket.
11) D.O. probe connector.
12) RS232 serial communication connector.
10
RS232
PROBEPOWER
12VDC
Front Panel
Primary LCD
Secondary LCD
1
2
4
6
3
11
Rear Panel
8
9
5
7
12
ppm
HI2400
Logging DO Meter
Functions
SETUP
LOG
RANGE
CFM CAL
Confirm Value
CFM
Change Value
/
Select Logging
LOG
View / Setup Parameters
SETUP
Start DO Calibration
CAL
Select DO Measurement
RANGE

6
HI 2400
SPECIFICATIONS
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OPERATIONAL GUIDE
POWER CONNECTION
Plug the 12 VDC adapter into the power supply socket.
Note: This instrument use non volatile memory to retain the calibration
parameters and all the other settings even when unplugged.
Note: Make sure a fuse protects the main line.
PROBE CONNECTION AND PREPARATION
To take measurements, connect the D.O. probe to the meter securely by
aligning the pins with the socket located on the back of the meter, pushing the
plug in and tightening the threaded ring.
Probes shipped from Hanna Instruments are dry. To hydrate the probe and
prepare it for use, connect it to the meter and proceed as follows:
1. Remove the red and black plastic cap.
This cap is for shipping purposes and
can be thrown away.
2. Wet the sensor by soaking the bottom
2½ cm (1") of the probe in electrolyte
(HI 7041S) for 5 minutes.
3. Rinse the membrane cap (HI 76407A
supplied in the kit with the meter) with
electrolyte solution while shaking it gen-
tly. Refill with clean electrolyte solution.
4. Tap gently the sides of the membrane
cap with your finger tip to ensure that
no air bubbles are trapped. To avoid
damaging the membrane, do not tap it
directly on the bottom.
5. Make sure that the rubber O-ring sits
properly inside the membrane cap.
6. With the sensor facing down, slowly screw
the cap clockwise. Some electrolyte will
overflow.
When not in use and during polarization (see page 8),
use the protective transparent cap supplied in the kit
with the meter.
Shipping
cap
black
red
FILL FIRST
THEN TAP
THEN SCREW
BACK ON

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INSTRUMENT START-UP
•Turn the instrument on by pressing the ON/OFF switch.
•All LCD tags are displayed and a beep is generated while the instrument
performs self test.
•After a few seconds “Cond” message appears on the LCD to inform the user
that the probe is in auto-conditioning (automatic polarization) mode.
•When this message disappears, the probe is polarized and the instrument
can be calibrated.
•If the probe is disconnected, the meter will display “----”.
PROBE POLARIZATION
The probe is under polarization with a fixed voltage of approximately 800 mV.
Probe polarization is essential for stable measurements with the same recur-
ring degree of accuracy.
With the probe properly polarized, oxygen is continually consumed when it
passes through the sensitive diaphragm and dissolves in the electrolyte solu-
tion contained in the probe.
If polarization is interrupted, the electrolyte solution continues to be enriched
with oxygen until it reaches an equilibrium with the surrounding solution.
Whenever measurements are taken with a non-polarized probe, the oxygen
level revealed is both that of the tested solution, as well as that present in the
electrolyte solution. This reading is incorrect.
The calibration of this instrument is very simple.
Before proceeding with the calibration, make sure the probe is ready for
measurements (see page 7), i.e. the membrane cap is filled with electrolyte
and the probe is connected to the meter and properly polarized.
For an accurate calibration, it is recommended to wait at least 15 minutes to
ensure precise conditioning of the probe.
Keep the protective cap on during polarization time and remove it for calibration
and measurements. Follow the calibration procedure (see page 10).
ppm
s
m
INTVDATETIME%
BUF
WRONG
CFM
NaCl
LOGCAL
ppm
g / l

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SALINITY AND ALTITUDE COMPENSATION
If the sample contains significant concentration of salinity or if you are performing
measurements at an altitude different from sea level, the read out values must
be corrected, taking into account the lower degree of oxygen solubility in these
situations (see pages 14-16).
Remember to set the altitude and/or the salinity before taking any D.O.
measurements. The meter will automatically compensate for these factors.
D.O. MEASUREMENTS
Make sure that the instrument has been calibrated and the
protective cap has been removed.
•Immerse the tip of the probe in the sample to be tested. Allow
approximately one minute for the reading to stabilize.
•The Dissolved Oxygen value (in %) is displayed on the primary LCD and
the temperature on the secondary LCD.
•Press RANGE to change the reading from % to ppm and vice-versa.
For accurate Dissolved Oxygen measurements, a water movement of 0.3 m/s
is required. This is to ensure that the oxygen-depleted membrane surface is
constantly replenished. A moving stream will provide adequate circulation.
The use of a magnetic stirrer to ensure a certain fluid velocity is recommended.
TEMPERATURE MEASUREMENTS
The probe has a built-in temperature sensor.
The measured temperature is indicated on the secondary LCD as shown above.
Allow the probe to reach thermal equilibrium before taking any measurement.
This can take several minutes. The greater the difference between the tem-
perature at which the probe was stored and the temperature of the sample,
the longer the time will be.
Note: If “----” is displayed, the D.O. probe is not properly connected or the
temperature is out of range. This also indicates the posibility of a
broken probe cable.
ppm
%

10
D.O. CALIBRATION
Calibrate the instrument frequently, especially if high accuracy is required.
The instrument can be calibrated in maximum 2 points: 0.0% (zero calibra-
tion) and 100.0% (slope calibration).
The zero calibration of the HI 2400 is very stable, therefore this procedure
needs to be performed only whenever the probe or the membrane is replaced.
However, because the slope calibration is more critical, it is recommended to
perform this procedure every week.
INITIAL PREPARATION
•Pour small quantities of HI 7040 Zero Oxygen
solution into a beaker. If possible, use a plastic
beaker to minimize any EMC interferences.
•Make sure the probe is ready for measurements (see probe preparation on
page 7), i.e. the membrane is filled with electrolyte and the probe is
connected to the meter.
•Switch the meter on by pressing the ON/OFF switch.
•For an accurate calibration, it is recommended to wait
for at least 15 minutes to ensure precise conditioning of
the probe.
•Remove the protective cap from the D.O. probe.
•Set the appropriate altitude factor (see page 14). Make
sure the salinity factor is set to zero (see page 13).
ZERO CALIBRATION
•Submerge the probe into HI 7040 zero oxygen solution
and stir gently for 2-3 minutes.
•Press CAL. The “~” tag will blink on the LCD until the
reading is stable.
•When the reading is stable, “CFM” starts blinking. Press
CFM to confirm the “0.0%” D.O. calibration.
•If the reading is within the limits (±15% f.s.), the
meter stores the value (and adjusts the slope point).
HI 7040
HI 7040
CFM
BUF
CAL
CFM
BUF
CAL %