Hanna Instruments HI96735C User manual

INSTRUCTION MANUAL
HI96735C
Hardness ISM

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.
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,

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TABLE OF CONTENTS
PRELIMINARY EXAMINATION ............................................................................................
GENERAL DESCRIPTION ....................................................................................................
ABBREVIATIONS ..............................................................................................................
SPECIFICATIONS ..............................................................................................................
PRECISION AND ACCURACY ..............................................................................................
PRINCIPLE OF OPERATION ...............................................................................................
FUNCTIONAL DESCRIPTION ...............................................................................................
ERRORS AND WARNINGS .................................................................................................
GENERAL TIPS FOR AN ACCURATE MEASUREMENT .............................................................
STARTUP ........................................................................................................................
MEASUREMENT PROCEDURE ............................................................................................
VALIDATION PROCEDURE .................................................................................................
CALIBRATION PROCEDURE ...............................................................................................
GLP ................................................................................................................................
BATTERY MANAGEMENT ...................................................................................................
BATTERY REPLACEMENT ...................................................................................................
ACCESSORIES ..................................................................................................................
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Please examine this product carefully. Make sure that the instrument is not damaged. If any damage
occurred during shipment, please contact your local Hanna Instruments Office.
Each HI96735 Ion Selective Meter is supplied complete with:
• Sample Cuvettes and Caps (2 pcs.)
• CAL Check™ standard cuvettes
• 9V Battery
• Scissors
• Cloth for wiping cuvettes
• Instrument quality certificate
• Instruction Manual and Quick Reference Guide
• Rigid carrying case
Internal design of carrying case can be different!
Note: Save all packing material until you are sure that the instrument works correctly. Any
defective item must be returned in its original packing.
PRELIMINARY EXAMINATION

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The HI96735 is an auto diagnostic portable microprocessor meter that benefits from
Hanna Instruments’ years of experience as a manufacturer of analytical instruments. It has the
advanced optical system based on a special Light Emitting Diode (LED) and a narrow band
interference filter that allows most accurate and repeatable readings. All instruments are factory
calibrated and the electronic and optical design minimizes the need of frequent calibration.
With the powerful CAL CheckTM validation function, you are able to validate good performance
of your instrument at any time. The validation procedure is extremely user friendly. Just use the
exclusive Hanna Instruments ready‑made, NIST traceable standards to verify the performance of
the instrument and recalibrate if necessary.
All instruments are splash proof and the LED and filter units are protected from dust or dirt by a
transparent cup. This makes the instruments fulfill field applications. Display messages aid the user
in routine operation. The meter has an auto shut off feature that will turn off the instrument after
10 minutes of non use in measurement mode or after 1 hour if left in calibration mode.
The meter uses an exclusive positive‑locking system to ensure that the cuvette is in the same
position every time it is placed into the measurement cell. It is designed to fit a cuvette with a
larger neck making it easier to add both sample and reagents. The cuvette is made from special
optical glass to obtain best results.
The HI96735 meter measures the hardness content in water samples in the 0 to 750 mg/L (ppm)
range. The method is an adaptation of the EPA recommended method 130.1.
The reagent is in powder form, supplied in packets and in liquid form, supplied in bottles and in
dropper bottles. The amount of reagent is precisely dosed to ensure the maximum repeatability.
GENERAL DESCRIPTION
degree Celsius
degree Fahrenheit
milligrams per liter. mg/L is equivalent to ppm (parts per million)
milliliter
millivolt
US Environmental Protection Agency
°C:
°F:
mg/L:
mL:
mV:
EPA:
ABBREVIATIONS

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SPECIFICATIONS
Range
LR 0 to 250 mg/L
MR 200 to 500 mg/L
HR 400 to 750 mg/L
Resolution 1 mg/L from 0 to 100 mg/L
5 mg/L from 100 to 750 mg/L
Accuracy
@25 °C (77 °F)
LR ±5mg/L ±4% of reading
MR ±7 mg/L ±3% of reading
HR ±10 mg/L ±2% of reading
Light Source Light Emitting Diode
Light Detector Silicon Photocell with narrow band interference filter @466 nm
Method
Adaptation of the EPA recommended method 130.1. The reaction
between calcium, magnezium and the reagents causes a red‑violet
tint in the sample.
Environment 0 to 50 °C (32 to 122 °F);
max 95% RH non‑condensing
Battery Type 9V (1 pc.)
Auto‑Shut off
After 10’ of non‑use in measurement mode;
after 1 hour of non‑use in calibration mode;
with last reading reminder
Dimensions 192 x 104 x 69 mm (7.6 x 4.1 x 2.7”)
Weight 320 g (11.3 oz.)
REQUIRED REAGENTS
Code Description Quantity/test
HI93735IND‑0 Indicator Reagent 0.5 mL
HI93735A‑XR (X=L, M, H) Liquid Reagent 9.0 mL
HI93735B‑0 Liquid Reagent 2 drops
HI93735C‑0 Powder Reagent 1 packet

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In a laboratory using a standard solution of the parameter and a representative lot of reagent (for
each parameter) the following standard deviations were obtained:
Precision is how closely repeated measurements
agree with each other. Precision is usually expressed
as standard deviation (SD).
Accuracy is defined as the nearness of a test result
to the true value.
Although good precision suggests good accuracy,
precise results can be inaccurate. The figure explains
these definitions.
PRECISION AND ACCURACY
Parameter Standard Solution Standard Deviation
Hardness LR 150 mg/L 10 mg/L
Hardness MR 350 mg/L 15 mg/L
Hardness HR 520 mg/L 20 mg/L

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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= ελc d
or
A = ελc d
Where:
‑log I/Io = Absorbance (A)
Io = intensity of incident light beam
I = intensity of light beam after absorption
ε
λ= molar extinction coefficient at wavelength λ
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 known.
Photometric chemical analysis is based on the possibility to develop an absorbing compound from a
specific chemical reaction between sample and reagents. Given that the absorption of a compound
strictly depends on the wavelength of the incident light beam, a narrow spectral bandwidth should
be selected as well as a proper central wavelength to optimize measurements.
PRINCIPLE OF OPERATION
The optical system of Hanna Instruments’ HI96735 colorimeter is based on special subminiature
LED and narrow‑band interference filters to guarantee both high performance and reliable results.
HI96735 block diagram (optical layout)
A microprocessor controlled special LED emits radiation which is first optically conditioned and
beamed to the sample contained in the cuvette. The optical path is fixed by the diameter of the
cuvette. Then the light is spectrally filtered to a narrow spectral bandwidth, to obtain a light beam
of intensity Ioor I.
The photoelectric cell collects the radiation Ithat is not absorbed by the sample and converts it
into an electric current, producing a potential in the mV range.

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The microprocessor uses this potential to convert the incoming value into the desired measuring
unit and to display it on the LCD.
The measurement process is carried out in two phases: first the meter is zeroed and then the actual
measurement is performed.
The cuvette has a very important role because it is an optical element and thus requires particular
attention. It is important that both, the measurement and the calibration (zeroing) cuvettes, are
optically identical to provide the same measurement conditions. Whenever possible use the same
cuvette for both. It is necessary that the surface of the cuvette is clean and not scratched. This to avoid
measurement interference due to unwanted reflection and absorption of light. It is recommended
not to touch the cuvette walls with hands.
Furthermore, in order to maintain the same conditions during the zeroing and the measuring phases,
it is necessary to close the cuvette to prevent any contamination.
PRINCIPLE OF OPERATION
INSTRUMENT DESCRIPTION
1) RANGE/GLP key
2) CAL CHECK key
3) ZERO/CFM key
4) READ /UNIT key
5) ON/OFF key
6) Liquid Crystal Display (LCD)
7) Cuvette alignment indicator
8) Cuvette holder
FUNCTIONAL DESCRIPTION
KEYPAD DESCRIPTION
• ON/OFF: to turn the meter on and off.
• ZERO/CFM: this is a bi‑functional key. Just press to zero the meter prior to measurement, or
confirm edited values. In calibration mode press to confirm factory calibration restore.
• READ /UNIT: this is a multi‑functional key. In measurement mode, press to make a
measurement, or press and hold for three seconds to change the measurement unit. In GLP
mode press to view the next screen.
• CAL CHECK: this is a bi‑functional key. Just press to perform the validation of the meter, or
press and hold for three seconds to enter calibration mode.
• RANGE/GLP : this is a multi‑functional key. In measurement mode, press to change the
parameter. Press and hold to enter GLP mode. In calibration mode press to edit the date and time.

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OPERATING MODES
• Measurement mode: default operation mode, enables both validation and measurement.
• Calibration mode: may be entered by keeping CAL CHECK pressed for three seconds (the
“CAL” tag appears), it enables calibration of the instrument.
• GLP mode: may be entered by pressing RANGE/GLP (“GLP” appears), it enables consulting
of user calibration date or restore factory calibration.
DISPLAY ELEMENTS DESCRIPTION
1) The measuring scheme (lamp, cuvette, detector), appears during different phases of zero or
reading measurement
2) Error messages and warnings
3) The battery icon shows the charging level of the battery
4) The hourglass appears when an internal checking is in progress
5) Status messages
6) The chronometer appears when the reaction timer is running
7) The month, day and date icons appear when a date is displayed
8) Four digit main display
9) Measuring units
10) Four digit secondary display
FUNCTIONAL DESCRIPTION