Hanna Instruments HI97725 User manual

INSTRUCTION MANUAL
HI97725
Free Chlorine,
Total Chlorine,
Cyanuric Acid & pH
Photometer

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 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,

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TABLE OF CONTENTS
TABLE OF CONTENTS
1. PRELIMINARY EXAMINATION ..........................................................................4
2. SAFETY MEASURES........................................................................................5
3. ABBREVIATIONS ...........................................................................................5
4. SPECIFICATIONS............................................................................................6
5. DESCRIPTION................................................................................................7
5.1. GENERAL DESCRIPTION & INTENDED USE..............................................7
5.2. FUNCTIONAL DESCRIPTION...................................................................8
5.3. PRECISION & ACCURACY.......................................................................9
5.4. PRINCIPLE OF OPERATION....................................................................9
5.5. OPTICAL SYSTEM................................................................................10
6. GENERAL OPERATIONS.................................................................................11
6.1. METER VALIDATION: CAL CHECK & CALIBRATION...................................11
6.2. GLP...................................................................................................13
6.3. LOGGING DATA & LOG RECALL ............................................................. 13
6.4. GENERAL SETUP ................................................................................14
6.5. REAGENTS & ACCESSORIES.................................................................16
6.6. CONTEXTUAL HELP............................................................................. 17
6.7. BATTERY MANAGEMENT ..................................................................... 17
7. PHOTOMETER..............................................................................................18
7.1. METHOD SELECTION .......................................................................... 18
7.2. COLLECTING & MEASURING SAMPLES AND REAGENTS...........................18
7.3. CUVETTE PREPARATION...................................................................... 19
8. METHOD PROCEDURE ..................................................................................20
8.1. FREE CHLORINE (POWDER REAGENT) .................................................. 20
8.2. FREE CHLORINE (LIQUID REAGENT)..................................................... 22
8.3. TOTAL CHLORINE (POWDER REAGENT).................................................25
8.4. TOTAL CHLORINE (LIQUID REAGENT) ...................................................27
8.5. CYANURIC ACID..................................................................................30
8.6. pH.................................................................................................... 32
9. WARNING & ERROR DESCRIPTIONS...............................................................34
10. BATTERY REPLACEMENT ............................................................................. 36
11. ACCESSORIES............................................................................................ 37
11.1. REAGENT SETS.................................................................................37
11.2. OTHER ACCESSORIES .......................................................................37
CERTIFICATION.................................................................................................38
RECOMMENDATIONS FOR USERS.......................................................................38
WARRANTY ......................................................................................................38

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PRELIMINARY EXAMINATION
1. PRELIMINARY EXAMINATION
Remove the instrument and accessories from the packaging and examine it carefully.
For further assistance, please contact your local Hanna Instruments Office or email us
at [email protected].
Each HI97725C 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 Check Cuvette A
• HI97701B - CAL Check Cuvette B for Free and Total Chlorine (Powder & Liquid)
• HI97710B - CAL Check Cuvette B for pH
• HI97722B - CAL Check Cuvette B for Cyanuric Acid
• Cloth for wiping cuvettes
• Scissors
• 1.5V AA Alkaline batteries
• CAL Check standard certificate
• Instrument quality certificate
• Instruction manual
Each HI97725 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
• Instrument quality certificate
• Instruction manual
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.

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SAFETY MEASURES
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.
3. ABBREVIATIONS
mg/L milligrams per liter (ppm)
mL milliliter
°C degree Celsius
°F degree Fahrenheit
EPA US Environmental Protection Agency
GLP Good Laboratory Practice
HDPE High Density Polyethylene
LED Light Emitting Diode
NIST National Institute of Standards and Technology
ABBREVIATIONS

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SPECIFICATIONS
4. SPECIFICATIONS
Chlorine
(All Methods)
Range 0.00 to 5.00 mg/L (as Cl2)
Resolution 0.01 mg/L
Accuracy ±0.03 mg/L ±3% of reading at 25 °C
Method Adaptation of US EPA Method 330.5, DPD
Colorimetric Method
Cyanuric Acid
Range 0 to 80 mg/L (as CYA)
Resolution 1 mg/L
Accuracy ±1 mg/L ±15% of reading at 25 °C
Method Adaptation of the Turbidimetric Method
pH
Range 6.5 to 8.5 pH
Resolution 0.1 pH
Accuracy ±0.1 pH of reading at 25 °C
Method Adaptation of the Phenol Red 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

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DESCRIPTION
5. DESCRIPTION
5.1. GENERAL DESCRIPTION & INTENDED USE
The HI97725 is an auto-diagnostic portable photometer 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 Instruments
CAL Check cuvettes are made with NIST traceable standards.
The built-in tutorial mode guides users step-by-step through the measurement
process. It includes all steps required for sample preparation, the required reagents
and quantities.
The HI97725 meter measures four important parameters in the treatment and
disinfection of drinking water, waste water, and swimming pools.
Chlorine is a widely used disinfectant. In order for chlorine to be effective the pH of the
water should be less then pH 8.0. The method is an adaptation of the US EPA Method
330.5, DPD Colorimetric Method.
Cyanuric Acid is added to increase the life of chlorine, without it chlorine levels can be
reduced by up to 90% in hours when exposed to sunlight. The method is an adaptation
of the Turbidimetric Method.
The method for pH is an adaptation of the Phenol Red Method.
The HI97725 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 key to perform the function displayed above it 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 & 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 and is method
specific.
Although good precision suggests good accuracy, precise results can be inaccurate. The
figure explains these definitions.
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. Photometric chemical analysis
is based on specific chemical reactions between a sample and reagent to produce a
light-absorbing compound.
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. If all other factors are constant, the
concentration "c" can be calculated form the absorbance of the substance.
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

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DESCRIPTION
5.5. OPTICAL SYSTEM
Instrument Block Diagram
The internal reference system (reference detector) of the HI97725 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.