Hanna Instruments HI97728 User manual

INSTRUCTION MANUAL
HI97728
Nitrate
Photometer

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 view our worldwide contact
list at www.hannainst.com.
Dear
Customer,
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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TABLE OF CONTENTS
1. PRELIMINARY EXAMINATION ..........................................................................4
2. SAFETY MEASURES........................................................................................4
3. SPECIFICATIONS............................................................................................5
4. ABBREVIATIONS ...........................................................................................5
5. DESCRIPTION................................................................................................6
5.1. GENERAL DESCRIPTION AND INTENDED USE ...........................................6
5.2. FUNCTIONAL DESCRIPTION ....................................................................7
5.3. PRECISION AND ACCURACY ....................................................................8
5.4. PRINCIPLE OF OPERATION .....................................................................8
5.5. OPTICAL SYSTEM...................................................................................9
6. GENERAL OPERATIONS...................................................................................9
6.1. METER VALIDATION: CAL CHECK/CALIBRATION......................................... 9
6.2. CHEMICAL FORMULA/UNIT CONVERSION ..............................................11
6.3. GLP....................................................................................................11
6.4. LOGGING DATA/LOG RECALL ................................................................. 12
6.5. GENERAL SETUP.................................................................................. 12
6.6. REAGENTS/ACCESSORIES..................................................................... 15
6.7. CONTEXTUAL HELP ..............................................................................15
6.8. BATTERY MANAGEMENT.......................................................................16
7. PHOTOMETER..............................................................................................16
7.1. PROPER USE OF POWDER PACKET ........................................................ 16
7.2. CUVETTE PREPARATION ....................................................................... 17
8. METHOD PROCEDURE ..................................................................................19
9. ERROR DESCRIPTIONS .................................................................................22
10. BATTERY REPLACEMENT ............................................................................. 23
11. ACCESSORIES............................................................................................ 24
11.1. REAGENT SETS..................................................................................24
11.2. OTHER ACCESSORIES......................................................................... 24
CERTIFICATION.................................................................................................25
RECOMMENDATIONS FOR USERS.......................................................................26
WARRANTY ......................................................................................................27
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PRELIMINARY EXAMINATION
1. PRELIMINARY EXAMINATION
Remove the instrument and accessories from the packaging and examine it carefully to
make sure that no damage has occurred during shipping. Notify your nearest Hanna
Customer Service Center if damage is observed.
Each HI97728C is delivered in a rugged carrying case and is supplied with:
• Sample cuvette (2 pcs.)
• Sample cuvette cap (2 pcs.)
• Plastic stopper (2 pcs.)
• A ZERO - CAL CheckCuvette A
• HI97728B -CAL Check Cuvette B for Nitrate
• Cloth for wiping cuvettes
• Scissors
• 1.5V AA Alkaline batteries
• Instruction manual
• Meter quality certificate
• CAL Check standard certificate
Each HI97728 is delivered in a cardboard box and is supplied with:
• Sample cuvette (2 pcs.)
• Sample cuvette cap (2 pcs.)
• Plastic stopper (2 pcs.)
• 1.5V AA Alkaline batteries
• Instruction manual
• Meter quality certificate
Note: Save all packing material until you are sure that the instrument works correctly.
Any damaged or defective item must be returned in its original packing material with
the supplied accessories.
2. SAFETY MEASURES
•The chemicals contained in the reagent kits may be hazardous if
improperly handled.
• Read the Safety Data Sheets (SDS) before performing tests.
• Safety equipment: Wear suitable eye protection and clothing when required, and
follow instructions carefully.
• Reagent spills: If a reagent spill occurs, wipe up immediately and rinse with plenty
of water. If reagent contacts skin, rinse the affected area thoroughly with water.
Avoid breathing released vapors.
• Waste disposal: For proper disposal of reagent kits and reacted samples, contact a
licensed waste disposal provider.
SAFETY MEASURES

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SPECIFICATIONS
3. SPECIFICATIONS
Nitrate
Range 0.0 to 30.0 mg/L (as NO3-N)
Resolution 0.1 mg/L
Accuracy ±0.5 mg/L ±10% of reading at 25 °C
Method Adaptation of Cadmium Reduction method
Measurement
System
Light source Light Emitting Diode
Bandpass filter 525 nm
Bandpass filter
bandwidth 8 nm
Bandpass filter
wavelength accuracy ±1.0 nm
Light detector Silicon photocell
Cuvette type Round 24.6 mm diameter (22 mm inside)
Additional
Specifications
Auto logging 50 readings
Display 128 x 64 pixel B/W LCD with backlight
Auto-off After 15 minutes of inactivity
(30 minutes before a READ measurement)
Battery type 1.5 V AA Alkaline (3 pcs.)
Battery life > 800 measurements (without backlight)
Environment 0 to 50 °C (32 to 122 °F);
0 to 100% RH, non-serviceable
Dimensions 142.5 x 102.5 x 50.5 mm (5.6 x 4.0 x 2.0")
Weight (with batteries) 380 g (13.4 oz.)
Case ingress
protection rating IP67, floating case
4. ABBREVIATIONS
mg/L milligrams per liter (ppm)
mL milliliter
°C degree Celsius
°F degree Fahrenheit
LED Light Emitting Diode
EPA US Environmental Protection Agency
HDPE High Density Polyethylene
GLP Good Laboratory Practice
NIST National Institute of Standards and Technology
ABBREVIATIONS

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DESCRIPTION
5. DESCRIPTION
5.1. GENERAL DESCRIPTION AND INTENDED USE
The HI97728 is an auto-diagnostic portable meter that benefits from Hanna’s years
of experience as a manufacturer of analytical instruments. It has an advanced optical
system that uses a Light Emitting Diode (LED) and a narrow band interference filter that
allows for accurate and repeatable readings.
The optical system is sealed from outside dust, dirt and water. The meter uses an
exclusive positive-locking system to ensure that the cuvettes are placed into the holder
in the same position every time.
With the CAL Check functionality, users are able to validate the performance of the
instrument at any time and apply a user calibration (if necessary). Hanna’s CAL Check
cuvettes are made with NIST traceable standards.
The built-in tutorial mode guides the users step-by-step through the measurement
process. It includes all steps required for sample preparation, the required reagents
and quantities.
The HI97728 meter measures the nitrate content in water samples in the 0.0 to 30.0
mg/L (ppm) as NO3-N range. The method is an adaptation of the Cadmium Reduction
method.
The HI97728 photometer is a compact and versatile meter suitable for field or bench
measurements, featuring a:
• Sophisticated optical system
• Meter validation using certified CAL Check cuvettes
• Tutorial mode guides the user step-by-step
• Auto logging
• Waterproof IP67, floating case
• GLP features

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DESCRIPTION
5.2. FUNCTIONAL DESCRIPTION
1) ON/OFF power button 3) Liquid Crystal Display (LCD) 5) Indexing mark
2) Keypad 4) Cuvette holder 6) Battery cover
Keypad Description
The keypad contains 3 direct keys and 3 functional keys with the following functions:
Press the functional keys to perform the function displayed above them on the LCD.
Press and hold to power off/on. Press briefly to return to the previous screen.
Press to access the menu screen.
Press to display the context-sensitive help menu.

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DESCRIPTION
5.3. PRECISION AND ACCURACY
Precision is how closely repeated
measurements are to one
another. Precision is usually
expressed as standard deviation
(SD).
Accuracy is defined as the
closeness of a test result to the
true value.
Although good precision suggests
good accuracy, precise results can
be inaccurate. The figure explains
these definitions.
For each method, the accuracy is expressed in the related measurement section.
5.4. PRINCIPLE OF OPERATION
Absorption of light is a typical phenomenon of interaction between electromagnetic
radiation and matter. When a light beam crosses a substance, some of the radiation
may be absorbed by atoms, molecules or crystal lattices.
If pure absorption occurs, the fraction of light absorbed depends both on the optical
path length through the matter and on the physical-chemical characteristics of the
substance according to the Lambert-Beer Law:
-log I/Io= elc d
or
A = elc d
Io= intensity of incident light beam
I= intensity of light beam after absorption
el= molar extinction coefficient at wavelength l
c = molar concentration of the substance
d = optical path through the substance
Therefore, the concentration “c” can be calculated from the absorbance of the substance
as the other factors are constant.
Photometric chemical analysis is based on specific chemical reactions between a
sample and reagent to produce a light-absorbing compound.

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DESCRIPTION GENERAL OPERATIONS
5.5. OPTICAL SYSTEM
Instrument Block Diagram
Theinternalreference system (reference detector) oftheHI97728 photometer compensates
for any drifts due to power fluctuations or ambient temperature changes, providing a
stable source of light for your blank (zero) measurement and sample measurement.
LED light sources offer superior performance compared to tungsten lamps. LEDs have a
much higher luminous efficiency, providing more light while using less power. They also
produce little heat, which could otherwise affect electronic stability. LEDs are available in
a wide array of wavelengths, whereas tungsten lamps have poor blue/violet light output.
Improved optical filters ensure greater wavelength accuracy and allow a brighter,
stronger signal to be received. The end result is higher measurement stability and less
wavelength error.
A focusing lens collects all of the light that exits the cuvette, eliminating errors from
cuvette imperfections and scratches, eliminating the need to index the cuvette.
6. GENERAL OPERATIONS
6.1. METER VALIDATION: CAL CHECK/CALIBRATION
Validation of the HI97728 involves verifying the concentration of the certified CAL
Check standards. The CAL Check screen guides the user step-by-step through the
validation process and user calibration (if necessary).
WARNING: Do not use any solutions/standards other than the Hanna®CAL Check
Standards. For accurate validation and calibration results, please perform these at
room temperature (18 to 25 °C; 64.5 to 77.0 °F).
Note: CAL Check Standards will not read the specified value in measurement mode.
Protect the CAL Check cuvettes from direct sunlight by keeping them in the original
packing. Store between +5 °C and +30 °C (41 - 86 °F), do not freeze.

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GENERAL OPERATIONS
To perform a CAL Check:
1. Press CAL Check key from measurement mode.
The “Not Available“ message or the date/time
and status of the last CAL Check will be displayed
on the screen.
2. Press the Check key to start a new CAL Check. Press
the key at any time to abort the validation
process.
3. Use the keys to enter the certificate value
of the calibration standard found on the CAL Check
Standard Certificate. Press Next to continue.
Note: This value will be saved in the instrument for future validation. If a new set
of calibration standards is obtained please update the certificate value.
4. Insert the A ZERO CAL Check Cuvette A then press
Next to continue. The “Please Wait...“ message
will be displayed during the measurement.
5. Insert the HI97728B CAL Check Cuvette B then
press Next to continue. The “Please Wait...“
message will be displayed during the measurement.
6. When the CAL Check is complete the display will
show one of the following messages and the value
obtained during the measurement:
- “PASSED“: The measured value is within the accuracy
specification, no user calibration is required.

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GENERAL OPERATIONS
- “OUT OF SPECIFICATION“ and the Calibration key is available: The measured
value is near the expected value. To update the user calibration press Calibrate.
Press Accept to confirm or Cancel to return to the previous screen.
- “OUT OF SPECIFICATION“: A user calibration is not allowed, the measured value is
outside of the tolerance window. Check the certified value, expiration date and clean
the outside of the cuvette. Repeat the CAL Check procedure. If this error continues
contact your nearest Hanna Customer Service Center.
6.2. CHEMICAL FORMULA/UNIT CONVERSION
Chemical formula/unit conversion factors are pre-programmed into the instrument
and are method specific. In order to view the displayed result in the desired chemical
formula enter menu by pressing and use the keys to select Chemical
Form. Press Select to change the displayed chemical form. Use the keys to
highlight the desired chemical formula and press Select. The selected formula will be
saved when the instrument is powered off.
6.3. GLP
Press the key to enter the menu. Use the 
keys to select GLP and press Select. Good Laboratory
Practice (GLP) shows the date and time of the last user
calibration (if available) or factory calibration. To erase
the last user calibration and to clear the CAL Check press Clear and follow the prompts.
Press Yes to erase and return to the factory calibration data or No to exit the clear
procedure.

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GENERAL OPERATIONS
6.4. LOGGING DATA/LOG RECALL
The instrument features a data autolog function to help users keep track of all
measurements. Every time a measurement is made the data is automatically saved.
The data log can hold 50 individual measurements. When the data log is full (50 data
points) the meter will rewrite the oldest data point.
Viewing and deleting the data is possible using the Log Recall menu.
Press the key to enter the menu. Use the functional keys to select Log
Recall and press Select.
Use the functional keys to highlight a log and press Info to view additional
information about the log. From this screen the Next and Previous keys can be used
to view other logs.
Use the Delete key to erase logged data. After pressing Delete a prompt on display
is asking for confirmation.
Press No or the key to return to the previous screen.
Press Yes to delete selected log.
Press Del All to erase all logged data.
If Del All is pressed follow the prompt to confirm.
Press Yes to delete all logged data, No or the key to return to the log recall.
6.5. GENERAL SETUP
Press the key to enter the menu. Use the keys to select Setup and press
Select. Use the keys to highlight desired option.

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GENERAL OPERATIONS
Backlight
Values: 0 to 100 %
Press the Modify key to access the backlight intensity.
Use the keys to increase or decrease the value.
Press the Accept key to confirm or the key to
return to the Setup menu without saving the new value.
Contrast
Values: 0 to 100 %
Press the Modify key to change the display’s contrast.
Use the keys to increase or decrease the value.
Press the Accept key to confirm the value or the
key to return to the Setup menu without saving the new
value.
Date/Time
Press the Modify key to change the date/time.
Press the keys to highlight the value to be
modified (year, month, day, hour, minute or second).
Press Edit to modify the highlighted value. Use the 
keys to change the value.
Press the Accept key to confirm or the key to
return to the previous screen.
Time Format
Option: AM/PM or 24-hour
Press the functional key to select the desired time format.

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GENERAL OPERATIONS
Date Format
Press the Modify key to change the date format.
Use the keys to select the desired format.
Press the Accept key to confirm or the key to
return to the Setup menu without saving the new format.
Decimal Separator
Option: Comma ( , ) or Period ( . )
Press the functional key to select the desired decimal
separator. The decimal separator is used on the
measurement screen.
Language
Press the Modify key to change the language. Use the
keys to select the desired language.
Press Accept to choose one of the languages installed.
Beeper
Option: Enable or Disable
When enabled, a short beep is heard every time a key is
pressed. A long beep alert sounds when the pressed key
is not active or an error is detected. Press the functional
key to enable/disable the beeper.
Tutorial
Option: Enable or Disable
When enabled, the user will be guided step-by-step
through the measurement procedure.

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GENERAL OPERATIONS
Meter Information
Press the Select key to view the model, serial number,
firmware version and selected language. Press the
key to return to the Setup menu.
Restore factory settings
Press the Select key to reset to factory settings.
Press Accept to confirm or Cancel to exit without
restoring the factory settings.
6.6. REAGENTS/ACCESSORIES
Press the key to enter the menu. Use the 
keys to select Reagents/Accessories and press Select
to access a list of reagents and accessories. To exit press
the key.
6.7. CONTEXTUAL HELP
The HI97728 offers an interactive contextual help mode
that assists the user at any time.
To access the help screen press the key.
The instrument will display additional information related to the current screen. To read
all the available information, scroll the text using the keys.
To exit help mode press the or the key and the meter will return to the
previous screen.

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GENERAL OPERATIONSPHOTOMETER
6.8. BATTERY MANAGEMENT
The meter will perform an auto-diagnostic test when it is powered on. During this test,
the Hanna®logo will appear on the LCD. After 5 seconds, if the test was successful,
the last method selected will appear on the display. The battery icon on the LCD will
indicate the battery status:
- battery full
- battery below 10%, replace the batteries soon
- battery is low, replace the batteries with new ones
To conserve battery, the meter will turn off automatically after 15 minutes of inactivity.
If a zero reading has been done but not a read, auto-off time is increased to 30 minutes.
7. PHOTOMETER
7.1. PROPER USE OF POWDER PACKET
(a) Use scissors to open the powder packet
(b) Push the edges of the packet to form a spout
(c) Pour out the content of the packet

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PHOTOMETER
7.2. CUVETTE PREPARATION
Proper mixing is very important for reproducibility of the measurements. The proper
mixing technique for each method is listed in the method procedure.
(a) Invert the cuvette a couple of times or for a specified time: hold the cuvette in the
vertical position. Turn the cuvette upside-down and wait for all of the solution to
flow to the cap end, then return the cuvette to the upright vertical position and
wait for all of the solution to flow to the cuvette bottom. This is one inversion.
The correct speed for this mixing technique is 10-15 complete inversions in 30
seconds. This mixing technique is indicated with “invert to mix” and the following
icon:
(b) The mixing method is indicated with “shake vigorously“ using one of the following
icons:
In order to avoid reagent leaking and to obtain more accurate measurements, close
the cuvette first with the supplied HDPE plastic stopper and then the black cap.

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PHOTOMETER
Whenever the cuvette is inserted into the measurement holder, it must be dry outside
and free of fingerprints, oil or dirt. Wipe it thoroughly with HI731318 or a lint-free
cloth prior to insertion.
Shaking the cuvette can generate bubbles in the sample, causing higher readings. To
obtain accurate measurements, remove such bubbles by swirling or by gently tapping
the cuvette.
Do not let the reacted sample stand too long after reagent has been added. For best
accuracy, respect the timings described in each specific method.
It is possible to take multiple readings in a row, but it is recommended to take a new
zero reading for each sample and to use the same cuvette for zeroing and measurement
when possible.
Discard the sample immediately after the reading has been taken, or the glass might
become permanently stained.
All the reaction times reported in this manual are at 25 °C (77 °F). In general, the
reaction time should be increased for temperatures lower than 20 °C (68 °F), and
decreased for temperatures higher than 25 °C (77 °F).

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METHOD PROCEDURE
8. METHOD PROCEDURE
REQUIRED REAGENTS
Code Description Quantity
HI93728-0 Nitrate Reagent 1 packet
REAGENT SETS
HI93728-01 Nitrate Reagent - 100 tests
HI93728-03 Nitrate Reagent - 300 tests
For other accessories see page 24.
MEASUREMENT PROCEDURE
Note: If tutorial mode is disabled follow the measurement procedure below. If the
tutorial mode is enabled, press Measure and follow the messages on the screen.
• Fill the cuvette with 10 mL of sample (up to the
mark). Replace the plastic stopper and the cap.
• Insert the cuvette into the holder and ensure that the
notch on the cap is positioned securely in the groove.
• Press the Zero key. The display will show “-0.0-” when the meter is zeroed and
ready for measurement.
• Remove the cuvette and add the content of one packet
of HI93728-0 Nitrate Reagent. Replace the plastic
stopper and the cap.
10 mL

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METHOD PROCEDURE
• Shake vigorously up and down for exactly 10
seconds. Continue to mix by inverting the cuvette
gently for 50 seconds, while taking care not to
induce air bubbles. Powder will not completely
dissolve. Time and method of shaking could
sensitively affect the measurement.
Note: The method is technique sensitive. For proper mixing technique see Cuvette
Preparation procedure detailed on page 17.
• Insert the cuvette into the holder and ensure that the notch
on the cap is positioned securely in the groove.
• Press the Read key and the display will show a 4 minute and 30 second countdown
prior to the measurement. To skip the timer press Read twice. When the timer ends
the meter will perform the reading. The instrument displays the results in mg/L of
nitrate-nitrogen (NO3-N).
• Press and use the keys to select Chemical Form.