Hanna Instruments HI 84429 User Manual
Instruction Manual
HI 84429
TITRATABLE ACIDITY
MINITITRATOR & pH METER
for Dairy Products
www.hannainst.com
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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 tech@hannainst.com.
TABLE OF CONTENTS
PRELIMINARY EXAMINATION................................................................................................. 3
GENERAL DESCRIPTION ........................................................................................................ 4
SPECIFICATIONS ................................................................................................................... 6
PRINCIPLE OF OPERATION .................................................................................................... 8
FUNCTIONAL DESCRIPTION................................................................................................... 9
TITRATOR STARTUP ........................................................................................................... 12
SETUP CONFIGURATION MENU .......................................................................................... 13
ELECTRODE PREPARATION .................................................................................................. 18
ELECTRODE CALIBRATION PROCEDURE................................................................................. 19
pH BUFFER TEMPERATURE DEPENDENCE ............................................................................ 23
PUMP TUBE INSTALLATION................................................................................................. 24
PURGE .............................................................................................................................. 24
PUMP CALIBRATION PROCEDURE ........................................................................................ 26
TITRATION PROCEDURE ..................................................................................................... 29
pH MEASUREMENT ............................................................................................................ 34
TEMPERATURE CALIBRATION PROCEDURE (for technical personnel only) ............................... 38
TROUBLESHOOTING GUIDE ................................................................................................ 40
ELECTRODE CONDITIONING & MAINTENANCE ...................................................................... 41
ACCESSORIES .....................................................................................................................42
WARRANTY........................................................................................................................43
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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PRELIMINARY EXAMINATION
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-M 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 large)
• 12 Vdc power adapter
• 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.
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GENERAL DESCRIPTION
The HI 84429 is an easy to use microprocessor-based automatic minititrator and pH meter designed
for the rapid and accurate analysis of Total Titratable Acidity in milk. By eliminating subjective
factors including color indicators, errors in mathematical calculations or erratic titrant additions from
the measurement, the HI 84429 makes Total Titratable acidity analysis precisely and totally
impartially. This will quickly become a valuable analysis tool in your dairy lab.
The instrument benefits from Hanna’s many years of experience as manufacturer of quality analytical
instruments. A clear and well-designed user interface makes the instrument intuitive and simple to
use. A dedicated HELP key aids in set-up, calibration, status and troubleshooting.
By simply pressing the Start key, the HI 84429 automatically starts pump operation and titrates the
sample to the end point. The HI 84429 has a simple and accurate peristaltic pump to ensure the best
accuracy and repeatability. By performing pump calibration with the Hanna standard provided, the
instrument accuracy is assured.
The instrument employs a powerful and effective built-in algorithm to analyze the pH response to
determine the exact pH endpoint, then uses this to make the necessary calculations. The Titratable
Acidity Determination is instantaneously display in user selected measurement units on the large dot
matrix display. The instrument is ready for the next analysis immediately!
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
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 6.50 to 6.70 pH at 25°C.
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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 7.00 or a phenolphtalein
endpoint of pH 8.30). 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:
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, diluted with 2 parts of distilled water, with 0.1N
NaOH, using phenolphtalein as indicator.
Dornic degrees (°D
This value is obtained by titrating 100 mL of milk, diluted with 2 parts of distilled water, with N/9
NaOH, using phenolphtalein as indicator.
Percent lactic acid (%l.a.
This value is obtained in the same way as °D, dividing the result by 100.
))
) - mostly used in Netherlands and France
))
))
) - frequently used in the UK, USA, Canada, Australia and New Zeeland
))
The result can be easily converted into any of the other units as shown in the table below:
HS°hT°D°.a.l%
52.01.0111.01110.0
15.252.25220.0
4.019.0900.0
9/49/011 10.0
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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 (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 800 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
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Temperature Range -20.0 to 120.0 °C (-4.0 to 248.0 °F)
Resolution 0.1 °C
Accuracy ±0.4 °C without probe error
Electrode FC 260B pH electrode (included)
HI 5315 reference electrode (included)
Temperature Probe HI 7662-M (included)
Environment 0 to 50 °C (32 to 122 °F); max 95% RH non-condensing
Power supply 12 Vdc power adapter
Dimensions 208 × 214 × 163 mm (8.2×8.4×6.4”) (with beaker)
Weight 2200 g (77 oz.)
REQUIRED REAGENTS
Code Description Quantity/Test
HI 84429-50 Titrant 0.5 mL
HI 84429-55 Standard 50 mL
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PRINCIPLE OF OPERATION
A neutralization titration is one where an acid and base react to form a neutral pH solution.
H++OH¯→H2O
A potentiometric acid-base titration employs an indicator electrode (such as a pH sensor) to establish
the equivalence point of the titration.
The accepted methodology for Titratable Acidity in dairy products employs a neutralization titration.
Acids (such as lactic acid) in the milk products react with a base (the titrant sodium hydroxide) to
produce water. When manually performed, the exact sample volume, titrant volume and titrant
concentration must be known. Additionally, the endpoint determination can be subjective when a
visual indicator (phenolphthalein) is utilized in an opaque or colored sample. Calculations are then
required. The entire procedure can be quite time consuming.
Titratable Acidity in dairy products, as performed on the HI 84429 minititrator, utilizes a simple
sample preparation, a high quality peristaltic dosing pump for titrant, potentiometric endpoint
detector and instantaneaous computations. To maintain the high precision of the titrator, a simple
pump calibration procedure is required. The calibration involves the analysis of a known volume of
a known solution (standard provided) and compensates for changes in pump dosing that may occur
due to many factors including tube stretching or aging. This procedure should be performed regularly.
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FUNCTIONAL DESCRIPTION
FRONT PANEL
1. Titrant bottle 3. Keypad 5. Peristaltic pump tubes
2. Graphic LCD 4. Electrode holder
REAR PANEL
6. pH Electrode 10. Power adapter connector 14. Power switch
7. Temperature probe 11. Reference electrode socket 15. Peristaltic pump
8. Reference electrode 12. BNC electrode connector
9. Beaker 13. Temperature probe socket
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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 stirrer starts automatically during pump calibration and titration and cannot be
stopped by pressing STIR key.
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GUIDE TO INCDICATORS
During the instrument’s operation a set of information are displayed on the LCD.
Displayed icons:
Unstable reading.
Stirrer on.
1
2
3
4
5
Pump activity.
Parameter can be changed.
1. Current time and instrument mode information (pH meter or Titrator)
2. pH electrode condition information
3. Main reading information
4. Instrument status information
5. Functional key area
6. Indicates that the displayed value can be changed using ARROW keys
7. Temperature reading display
8. pH temperature compensation mode (manual or Automatic)
9. Stirrer and reading status area
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8
7
6
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PERISTALTIC PUMP
Peristaltic pumps are self priming. Liquid never contacts the pump components. The titrant tubing
is pressed along the rotating rollers of the pump. The rollers compress the tubing drawing titrant
along and out the titrator tip.
TITRATOR STARTUP
• Place the instrument on a flat table. Do not place the instrument in direct sun light.
• Connect the power adapter to the instrument.
• Turn the instrument ON using the power switch from the rear panel of the instrument.
• Set up the instrument. See the “Setup Configuration Menu” section for details.
• Prepare the electrodes and attach pH sensor and reference electrode to the instrument.
• Calibrate the pH electrode. At least a single point calibration in 8.30 pH buffer is necessary
for titration.
• Place the peristaltic pump tube on the pump. See the “Pump Tube Replacement” section for
the procedure.
• Remove the reagent bottle cap and replace the bottle cap with the tubes. Place the reagent
bottle in the appropriate place on the titrator top.
• Connect the tubes with the peristaltic pump (inlet tube is connected with the reagent bottle,
outlet tube is connected with the dosing tip).
• Purge line.
• Calibrate the pump.
• Select Low Range in “Acidity Titration” setup parameter.
• Prepare the sample.
• Run a titration and log sample results.
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SETUP CONFIGURATION MENU
The titrator’s setup configuration menu may be accessed from the pH or titration screens by
pressing the MENU key, then Setup.
A list of setup parameters will be displayed with currently configured setting.
While in the setup menu it is possible to modify the instrument’s operation parameters. The
ARROW keys permit the user to scroll the setup parameters.
Press HELP to view the contextual help.
Press ESC to return to the main screen.
Concentration unit
Option: °SH, °Th, °D, % l.a.
Press the corresponding function key to change the
option.
Acidity titration
Option: Low Range, High Range.
From your knowledge of expected concentrations,
use the table below to determine which settings are
appropriate.
Press the corresponding function key to select the
new option.
Note: The milk sample size will change with these settings:
TINUegnaRwoL
HS°0.51ot0.00.57ot0.01
HT°04ot0002ot02
D°53ot0571ot02
.a.l
%53.0ot00.00.2ot0.0
)elpmasklimLm05(
egnaRhgiH
)elpmasklimLm01(
Select Low Range for dairy products in the 0 to 15 °SH range. Select High Range for dairy
product in the 10 to 75 °SH range. The titrant solution remains the same for either selection.
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Calibration timeout
pH resolution
Option: Disabled or 1 to 7 days.
This option is used to set the number of days
before the pH calibration expired warning message
is flagged.
Press Modify to access the calibration timeout
value modify parameter.
Use the ARROW keys in order to increase/decrease
the value.
Press Accept to confirm or ESC to return to the
setup menu without saving the new value.
Option: 0.1 or 0.01.
Press the displayed function key in order to change
the option.
Temperature unit
Backlight
Option: °C or °F.
Press the function key in order to change the option.
Option: 0 to 8.
Press Modify to access the backlight value.
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