Hanna Instruments HI 84429 User manual

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Instruction Manual
HI 84429
TITRATABLE ACIDITY
MINITITRATOR & pH METER
for Dairy Products
www.hannainst.com

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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.
Dear Customer,
Thank you for choosing a Hanna product. This manual will provide you with the necessary
information for the correct use of the instrument. Please read it carefully before using the meter. If
you need additional technical information, do not hesitate to e-mail us at [email protected].
This instrument is in compliance with directives.
TABLE OF CONTENTS
PRELIMINARY EXAMINATION................................................................................................. 3
GENERAL DESCRIPTION ........................................................................................................ 3
SPECIFICATIONS ................................................................................................................... 6
PRINCIPLE OF OPERATION .................................................................................................... 8
FUNCTIONAL DESCRIPTION................................................................................................... 9
TITRATOR STARTUP ........................................................................................................... 11
SETUP CONFIGURATION MENU .......................................................................................... 12
ELECTRODE PREPARATION .................................................................................................. 18
ELECTRODE CALIBRATION PROCEDURE................................................................................. 19
pH BUFFER TEMPERATURE DEPENDENCE............................................................................ 23
PUMP TUBE REPLACEMENT ................................................................................................ 24
PURGE .............................................................................................................................. 24
PUMP CALIBRATION PROCEDURE ........................................................................................ 26
TITRATION PROCEDURE ..................................................................................................... 29
pH MEASUREMENT ............................................................................................................ 34
TEMPERATURE CALIBRATION PROCEDURE (for technical personnel only) ............................... 38
PC INTERFACE ................................................................................................................... 40
FUSE REPLACEMENT .......................................................................................................... 43
TROUBLESHOOTING GUIDE ................................................................................................ 44
ELECTRODE CONDITIONING & MAINTENANCE ...................................................................... 45
ACCESSORIES .....................................................................................................................46
WARRANTY........................................................................................................................47

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Please examine this product carefully. Make sure that the instrument is not damaged. If any
damage occured during shipment, please notify your Dealer.
Each HI 84429 minititrator is supplied complete with:
•FC 260B pH electrode
•HI 5315 Reference electrode
•HI 7072 Filling solution (30 mL)
•HI 7662-T Temperature probe
•HI 84429-50 Titrant (100 mL)
•HI 84429-55 Standard (500 mL)
•HI 700640 Cleaning solution for milk deposits (2x20mL)
•pH 4.01 buffer solution (230 mL)
•pH 6.00 buffer solution (230 mL)
•pH 8.30 buffer solution (230 mL)
• Two 50 mL beakers
• Two 20 mL beakers
• Tube set with cap
• Stir bars (2 small & 2 large)
• Power cord
• One 1 mL syringe
• One capillary dropper pipette
• Instruction manual
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
The HI 84429 is a valuable, easy to use, microprocessor-based automatic titrator and pH meter that
benefits from Hanna’s years of experience as manufacturer of analytical instruments.
It has a simple and accurate peristaltic pump to ensure the best accuracy and repeatability. By performing
pump calibration with the provided Hanna standards, the instrument accuracy is assured.
The instrument comes with a preprogrammed analysis method designed for Total Titratable Acidity
measurements on milk.
The HI 84429 performs automatic analysis, all the necessary calculations and assures to the user a simple
and effective interface.
The instrument has a powerful and effective built-in algorithm to analyze the shape of the pH electrode
response and to determine the reaction completion.
By simply pressing the Start key, the instrument will automatically titrate the acidity up to the end point.
The result is immediately displayed in convenient units, then the instrument is ready for another titration.
GENERAL DESCRIPTION

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Other features:
• Log on demand up to 100 samples (50 for pH measurement; 50 for titration results)
• GLP feature, to view last calibration data for pH electrode and pump
• PC interface
MEASUREMENT SIGNIFICANCE
Both pH and titratable acidity are used to measure milk acidity. A decrease in pH or increase in
titratable acidity indicates lactic fermentation has occurred, most likely due to bacterial activity. pH
and titratable acidity measurements, together with other tests available to the analyst, provide a
mechanism to ensure quality and freshness of the milk products.
The pH of milk (or other dairy products) is a measurement of the actual acidity of the milk at the time
of measurement. The measurement uses a pH electrode and pH meter that reads out directly in units
of pH after calibrating the electrode and meter together using pH buffers. The pH of fresh milk is
slightly acidic typically falling between 6.5 to 6.7 pH at 25°C.
Titratable acidity measures the total titratable acidity and differs from pH as it also includes the
buffering capacity of the milk constituents. Titratable acidity in dairy products, is determined by
titrating a sample with sodium hydroxide to a fixed endpoint pH (pH 7.0 or a phenolphtalein
endpoint of pH 8.3). The actual neutralization of milk occurs at an endpoint of pH 7.00, however
standard methods utilize the phenolphtalein endpoint value. The results will differ depending upon
which endpoint is utilized. The endpoint can be determined visually using color change produced by
phenolphtalein indicator or less subjectively, using a pH electrode as the indicator in a potentiometric
acid-base titration.
Titratable acidity can be expressed in various units values basically expressed as a result of the
strength of the sodium hydroxide (NaOH) needed for titration:
Soxhlet Henkel degrees (°SH)- mostly used in Central Europe
This value is obtained by titrating 100 mL of milk with 0.25N NaOH, using phenolphtalein as indicator.
Thorner degrees (°Th)- mostly used in Sweden and the CIS
This value is obtained by titrating 100 mL of milk, thinned with 2 parks of distilled water, with 0.1N
NaOH, using phenolphtalein as indicator.
Dornic degrees (°D))
))
)- mostly used in Netherlands and France
This value is obtained by titrating 100 mL of milk, thinned with 2 parks of distilled water, with N/9
NaOH, using phenolphtalein as indicator.
Percent lactic acid (%l.a.))
))
)- frequently used in the UK, USA, Canada, Australia and New Zeeland
This value is obtained in the same way as °D, diving the result by 100.

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Taking into account the concentration of sodium hydroxide the result expressed into one unit value
can be easily converted into any other unit value according with the chart:
°SH °Th °D %l.a.
NaOH conc. (N) 0.25 0.1 0.111 0.0111
1 2.5 2.25 0.0225
0.4 1 0.9 0.009
4/9 10/9 1 0.01
The HI 84429 minititrator permits the measurement of both pH and titratable acidity of dairy products.
The titration method is a potentiometric end point determination at fixed pH value of 8.30.
The HI 84429 minititrator eliminates the subjective end point detection given by the human
eye, thus eliminating the errors that can appear in the results.
Acidity of dairy products can be measured in any of the unit values described previously by selecting
the desired unit value. Furthermore, by performing a pump calibration with the supplied standard
titrations with widely varying values may be made without changing the tubes or purging the titrant
in order to clean the tubes.

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SPECIFICATIONS
Titrator Range Titratable acidity (low range)
°SH: 0.0 to 15.0 °SH
°Th: 0 to 40 °Th
°D: 0 to 35 °D
%I.a.: 0.00 to 0.35 %I.a.
Titratable acidity HR (high range)
°SH: 10.0 to 75.0 °SH
°Th: 20 to 200 °Th
°D: 20 to 175 °D
%I.a.: 0.0 to 2.0 %I.a.
Resolution Titratable acidity (low range):
0.1 °SH
1 °Th
1 °D
0.01 %I.a.
Titratable acidity (high range):
0.5 °SH
1 °Th
1 °D
0.1 %I.a.
Accuracy 5% of reading
Titration method Acid-base titration
Principle End point titration, 8.30 pH
Pump debit 0.5 ml/min
Stirring speed 1500 rpm
Log data Up to 50 samples
pH meter pH meter -2.0 to 16.0 pH / -2.00 to 16.00 pH
pH Resolution: 0.1 pH / 0.01 pH
pH Accuracy: ± 0.01 pH
pH Calibration: 1, 2 or 3 point calibration;
3 available buffers (4.01, 6.00, 8.30)
Temperature manual or automatic from
compensation: -20 to 120 °C (-4 to 248 °F)
Log data Up to 50 samples
Temperature Range -20.0 to 120.0 °C (-4.0 to 248.0 °F)

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Resolution 0.1 °C
Accuracy ±0.4 °C without probe error
REQUIRED REAGENTS
Code Description Quantity/Test
HI 84429-50 Titrant 0.5 mL
HI 84429-55 Standard 50 mL
Electrode FC 260B pH electrode (included)
HI 5315 reference electrode (included)
Temperature Probe HI 7662-T (included)
Environment 0 to 50 °C (32 to 122 °F); max 95% RH non-condensing
Power supply 220 V/50Hz; 115 V/60Hz; 10 VA
Dimensions 208 × 214 × 163 mm (8.2×8.4×6.4”) (with beaker)
Weight 2200 g (77 oz.)

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PRINCIPLE OF OPERATION
The determination of titratable acidity in dairy products is made according to a neutralization
reaction, that is the reaction between the acids found in dairy products and a base. This type of
reaction forms the basis of titration methods of analyzing acids.
Titratable acidity is measured on a sample by titrating the sample with sodium hydroxide to an endpoint
of 8.30 pH. The results are expressed in °SH, °Th, °D or %l.a. according with the setup selection.
For precise results it is very important to know the exact sample volume, titrant volume and
concentration. Also it is better to select the titration low range or high range according to the
expected acidity of the sample.
The peristaltic pump has good repeatability but the dosing volume depends on many factors including the
diameter of the tube or the tube stretching. To compensate, the pump needs to be calibrated. The calibration
of the pump is also needed in order to have high precision of the titrations.
The calibration procedure is the analysis of a known solution which has a known volume. By doing this,
the instrument makes a differential analysis between the standard and the dairy product sample. The pump
volumetric debit and the real concentration of the titrant is compensated.

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FUNCTIONAL AND PHYSICAL DESCRIPTION
FRONT PANELFRONT PANEL
FRONT PANELFRONT PANEL
FRONT PANEL
1. Titrant bottle 3. Keypad 5. Peristaltic pump tubes
2. Graphic LCD 4. Electrode holder
REAR PANELREAR PANEL
REAR PANELREAR PANEL
REAR PANEL
6. pH Electrode 11. Reference electrode socket 16. Power switch
7. Temperature probe 12. BNC electrode connector 17. Power cable connector
8. Reference electrode 13. Temperature probe socket 18. Peristaltic pump
9. Beaker 14. USB connector
10. RS232 connector 15. Fuse

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KEYPAD FUNCTION AND INDICATORS
ESC - used to leave the current screen and to return either to the previous screen or to the
main screen, depending on the context, while pressed in SETUP the new value of
the set parameter is not changed.
/ - used to modify a parameter’s value, to scroll the information displayed while
viewing a help or to move between the options from the instrument’s setup
HELP - used to access/leave the instrument’s contextual help
MENU - used to enter Setup, Recall or GLP selection menu, while instrument is in pH or
titration main screen
STIR - used to start/stop the stirrer.
Note: The stirer starts automatically during pump calibration and titration and cannot be
stopped by pressing STIR key.
1) Current time and instrument mode information (pH meter or Titrator)
2) pH electrode condition information
3) main reading information
4) instrument status information
GUIDE TO INCDICATORS
During the instrument’s operation a set of information are displayed on the LCD.
Displayed icons:
Unstable reading.
Stirrer on.
Pump activity.
Parameter can be changed.
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