Hanna Instruments HI 96821 User manual

HI96821
Refractometer for Sodium
Chloride Measurements
INSTRUCTION MANUAL

Thank you for choosing a Hanna Instruments product.
Please read this instruction manual carefully before using
this instrument.
This manual will provide you with the necessary information
for correct use of this 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
Preliminary Examination .......................................................
General Description...............................................................
Specifications.......................................................................
Principle of Operation...........................................................
Functional Description...........................................................
Display Elements..................................................................
Measurement Guidelines .......................................................
Calibration Procedure............................................................
Measurement Procedure........................................................
To Change Measurement Unit................................................
To Change Temperature Unit .................................................
Making a Standard Sodium Chloride Solution.........................
Battery Replacement.............................................................
Error Messages.....................................................................
Accessories...........................................................................
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Remove the instrument from the packing materials and examine carefully
to ensure no damage has occurred during shipping. If any damage has
occurred, contact your local Hanna Instruments Office.
Each HI96821 instrument is supplied with:
• 9 V battery
• Instruction manual
• Plastic pipette
• Quality Certificate
Note: Save all packing material until you are sure that the instrument
functions correctly. A defective instrument must be returned in its
original packing.
PRELIMINARY EXAMINATION

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The HI96821 Digital Refractometer is a rugged portable, water resistant
device that benefits from Hanna Instruments’ years of experience as a
manufacturer of analytical instruments.
The HI96821 is an optical instrument that employs the measurement of
the refractive index to determine sodium chloride concentration in aqueous
solutions used in food preparation. It is not intended for sea water salinity
measurements. The measurement of refractive index is simple and quick and
provides the user an accepted method for NaCl analysis. Samples are mea‑
sured after a simple user calibration with deionized or distilled water. Within
seconds the instrument measures the refractive index of the solution. The
digital refractometer eliminates the uncertainty associated with mechanical
refractometers and is easily portable for measurements where you need them.
Theinstrumentutilizesinternationallyrecognizedreferencesforunitconversion
and temperature compensation. It can display the measurement of NaCl con‑
centration4differentways:g/100g, g/100mL,SpecificGravityand°Baumé.
Temperature (in °C or °F) is displayed simultaneously with the measurement
on the large dual level display along with icons for Low Power and other
helpful message codes.
Key features include:
• Waterproof models offers IP65 waterproof protection
• Automatic Temperature Compensation (ATC)
• Battery operation with Low Power indicator (BEPS)
• Automatically turns off after 3 minutes of non‑use
GENERAL DESCRIPTION

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Range
g/100 g: 0.0 to 28.0
g/100 mL: 0.0 to 34.0
Specific Gravity: 1.000 to 1.216
˚Baumé: 0.0 to 26.0
˚C (˚F): 0.0 to 80.0 ˚C
(32.0 to 176.0 ˚F)
Resolution
g/100 g: 0.1
g/100 mL: 0.1
Specific Gravity: 0.001
˚Baumé: 0.1
˚C (˚F): 0.1 ˚C (0.1 ˚F)
Accuracy
g/100 g: ±0.2
g/100 mL: ±0.2
Specific Gravity: ±0.002
˚Baumé: ±0.2
˚C (˚F): ±0.3 ˚C (±0.5 ˚F)
Temperature Compensation Automatic between 10.0 and 40.0 °C
(50.0 ‑ 104.0 °F)
Measurement Time Approximately 1.5 seconds
Minimum Sample Volume 100 µL (cover prism totally)
Light Source Yellow LED
Sample Cell Stainless Steel ring and flint glass prism
Case Material ABS
Enclosure Rating IP65
Battery Type / Life 9V / 5000 readings
Auto‑Off After 3 minutes of non‑use
Dimensions 192 x 102 x 69 mm (7.6 x 4.1 x 2.7”)
Mass 350 g (12.3 oz)
SPECIFICATIONS

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PRINCIPLE OF OPERATION
Aqueous NaCl determinations are made by measuring the refractive index of
a solution. Refractive Index is an optical characteristic of a substance and the
number of dissolved particles in it. Refractive Index is defined as the ratio of
the speed of light in empty space to the speed of light in the substance. A
result of this property is that light will “bend”, or change direction, when it
travelsthroughasubstanceofdifferentrefractiveindex.Thisiscalledrefraction.
When passing from a material with a higher to lower refractive index, there
is a critical angle at which an incoming beam of light can no longer refract,
but will instead be reflected off the interface.
The criticalangle canbe usedto easilycalculate therefractive indexaccording
to the equation:
sin (θcritical) = n2/ n1
Wheren2istherefractiveindexofthelower‑densitymedium;n1istherefractive
index of the higher‑density medium.
In the HI96821 refractometer, light from an LED passes through a prism in
contact with the sample. An image sensor determines the critical angle at
which the light is no longer refracted through the sample.
Specialized algorithms then apply temperature compensation to the
measurement and convert the refractive index to: g/100 g (% by mass),
g/100 mL, Specific Gravity (S.G. 20/20) or °Baumé.

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1. Liquid Crystal Display (LCD)
2. Secondary Display
3. Primary Display
4. READ Key (User Measurement)
5. ZERO Key (User Calibration)
6. RANGE Key (User Measurement Unit)
7. ON/OFF
8. Stainless Steel Sample Well and Prism
TOP VIEW
FUNCTIONAL DESCRIPTION
9. Battery Cover
10. Battery Compartment
BOTTOM

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1. Battery (blinks when low battery condition detected)
2. Primary Display (displays measurement and error messages)
3. Measurement in Progress Tag
4. SETUP: Factory Calibration Tag
5. CAL: Calibration Tag
6. Measurement Units
7. Automatic Temperature Compensation
(blinks when temperature exceeds 10.0‑40.0 °C /50.0‑104.0 °F range)
8. Temperature Units
9. Secondary Display (displays temperature measurements; when blinking,
temperature has exceeded operation range: 0.0‑80.0 °C/32.0‑176.0 °F)
DISPLAY ELEMENTS

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• Handle instrument carefully. Do not drop.
• Do not immerse instrument under water.
• Do not spray water to any part of instrument except the “sample well”
located over the prism.
• The instrument is intended to measure sodium chloride solutions. Do not
expose instrument or prism to solvents that will damage it. This includes
most organic solvents and extremely hot or cold solutions.
• Particulate matter in a sample may scratch the prism. Absorb sample
with a soft tissue and rinse sample well with deionized or distilled water
between samples.
• Use plastic pipettes to transfer all solutions. Do not use metallic tools
such as needles, spoons or tweezers as these will scratch the prism.
• Cover sample well with hand if measuring in direct sun.
• To reduce the effects of evaporation or absorption of water when taking
readings over a period of time, the prism and sample well can be covered
with plastic wrap.
MEASUREMENT GUIDELINES