Milwaukee MI455 User manual

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Milwaukee WMilwaukee W
Milwaukee WMilwaukee W
Milwaukee Wine Line L
ine Line L
ine Lab Minititratorab Minititrator
ab Minititratorab Minititrator
ab Minititrator
Mi455
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Free & Tree & T
ree & Tree & T
ree & Total Sulphur Dioxideotal Sulphur Dioxide
otal Sulphur Dioxideotal Sulphur Dioxide
otal Sulphur Dioxide
INSTRUCTION MANUAL

Instruction Manual Mi455 FREE & TOTAL SULPHUR DIOXIDE Minititrator for wine analysis
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FUNCTIONAL DESCRIPTION ............................................................................... 3
GENERAL DESCRIPTION ..................................................................................... 4
PRINCIPLE OF OPERATION .................................................................................. 6
SPECIFICATIONS ............................................................................................... 7
STARTUP ........................................................................................................... 8
GUIDE TO DISPLAY CODES ................................................................................. 9
GENERAL TIPS FOR AN ACCURATE MEASUREMENT ............................................... 11
PUMP CALIBRATION PROCEDURE ...................................................................... 11
FREE SO2MEASUREMENT PROCEDURE ............................................................... 13
TOTAL SO2MEASUREMENT PROCEDURE ............................................................. 14
PUMP TUBE REPLACEMENT ................................................................................ 15
FUSE REPLACEMENT ......................................................................................... 16
ELECTRODE CONDITIONING AND MAINTENANCE ............................................. 16
ACCESSORIES ................................................................................................. 18
TABLE OF CONTENTS

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FUNCTIONALDESCRIPTION
FRONT PANEL
A. TITRANT BOTTLE
B. LIQUID CRYSTAL DISPLAY (LCD)
C. KEYPAD
D. ELECTRODE HOLDER
DISPLAY
A. HOURGLASS ICON
B. BATTERY STATUS ICON
C. ERROR MESSAGE
D. MEASURE STATUS
E. CALIBRATION MODE INDICATOR
F. MAIN DISPLAY
G. MEASUREMENT UNIT
H. TIMER MODE INDICATOR
I. SECONDARY DISPLAY
REAR PANEL
E. ORP ELECTRODE
F. PERISTALTIC PUMP TUBE
G. BEAKER
H. PERISTALTIC PUMP
I. BNC ELECTRODE CONNECTOR
J. FUSE
K. POWER CABLE CONNECTOR
L. POWER SWITCH

Instruction Manual Mi455 FREE & TOTAL SULPHUR DIOXIDE Minititrator for wine analysis
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GENERAL DESCRIPTION
The Mi455 is a low-cost, easy to use, microprocessor-based automatic titrator. It has a
simple and reliable peristaltic pump that ensure high dosing repeatability. By performing
pump calibration with the provided Milwaukee standards, the instrument accuracy is assured.
The instrument comes with a pre-programmed analysis method designed for Free and
Total Sulphur Dioxide measurements on wine samples. The instrument has a powerful
and effective built-in algorithm to analyze the shape of the electrode response and to
determine the reaction completion. This algorithm automatizes the analysis, makes all
the necessary calculations and assures a simple and effective interface for the user.
By simply pressing the START STOP button, the instrument will automatically make the
titration up to the equivalence point. The result is immediately displayed in convenient
units, then the instrument is ready for another titration.
SIGNIFICANCE OF USE
An important reason for adding SO2 is to avoid oxidation. When there is oxygen around,
SO2itself becomes oxidized before phenol compounds in the wine , and so acts as an oxygen
scavenger. Also SO2 suppresses the activity of enzymes that cause browning and other
problems.
What is really protecting your wine is molecular SO2. When you add SO2, depending of
circumstances, some of it immediately becomes bound. The relationship between the
amount of added SO2and the amount of SO2remaining free is complex. It is clear,
however, that it is largely governed by the total SO2content of the wine. The rate of binding
decreases as the free SO2concentration increases. The exact relationship between free
and bound (total - free) SO2will vary from wine to wine.
Below 30-60 ppm, 33% to 50% of SO2addition becomes bounded. What remains is
called “free” and it is divided in two parts. The larger, and relatively ineffective free part is
KEYPAD
A. PUMP - to start/stop the pump
B. CAL - to enter pump calibration mode
C. STIR - to start/stop the stirrer while in
measurement or purging mode
D. START STOP - to start/stop titration or
pump calibration

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“bisulphite” (HSO3-). The smaller part of the free is the active molecular SO2. The amount
of molecular SO2in your wine depends both on the level of free SO2present as well as pH.
For instance, at pH 3.2, the amount of free SO2for 0.8 ppm molecular SO2is 22 ppm. At
pH 3.5, you will need 43 ppm free - essentially double.
This meter is supplied with:
• Reagents set for 20 titrations
• Two 50 mL beakers
• Two 20 mL beakers
• Tubes set with cap
• ORP probe
• Stir bar
• Power cable
• One 230 mL bottle of Refill Solution
• One 1 mL syringe
• Instruction manual
• Warranty code
Note: Save all packing material until you are sure that the instrument works correctly.
Any defective item must be returned in its original packing.
Free SO2concentration (ppm) for 0.8 ppm molecular SO2:
In most situations, 0.8 ppm molecular SO2during bulk storage and at bottling will provide
you with adequate protection from oxidation and bacterial action. This includes prevention
of malolactic bacteria as well.
It is important to remember that the amount of free SO2in the wine depends on three
things: how much is added, how much was present before the addition and how much of
your addition promptly becomes bound.
The level at which molecular SO2can be detected by the human senses is about 2.0 ppm.
This is also the level which is needed for maximum protection of your wine. This is
particularly true in the case of sweet, and most notably, botrytised wines.
The Milwaukee Mi455 offers the possibility to test free or total SO2in all the wines
including the red ones, that are difficult to test with manual methods because the color
changes are hardly seen.
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PRINCIPLE OF OPERATION
Determination of sulphur dioxide in wine samples is made by titration of the sulphur
dioxide present in wine with iodate. In this procedure an excess of iodine is added to the
wine sample and it is titrated with iodate.
For precise results it is very important to know the exact sample volume, titrant volume and
concentration.
The peristaltic pump has a good repeatability but the dosing volume depends on many
factors as the diameter of the tube or the tube stretching. To compensate for all this errors,
the pump need to be calibrated. The calibration of the pump is also needed in order to have
high precision of the titrations.
The calibration procedure is in fact the analysis of a known solution. By doing this, the
instrument makes a differential analysis between the standard and the wine sample. The
pump volumetric debit and the real concentration of the titrant is compensated. Only the
sample volume has to be precisely known.

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This instrument is in compliance with CE Directives.
SPECIFICATIONS
Range 0 to 400 ppm SO2
Resolution 1 ppm
Accuracy 5% of reading
Method Ripper titrimetric method
Principle Equivalence point redox titration
Sample volume 50 mL
ORP Electrode MA924B/1 (included)
Pump debit 0.5 mL/min
Stirring speed 1500 rpm
Environment 0 to 50 °C (32 to 122 °F) ; max 95% RH non-condensing
Power supply 220V/50Hz; 10VA
Dimensions 208 x 214 x 163 mm (8.2 x 8.4 x 6.4") (with beaker)
Weight 2200 g (77,6 oz.).
Required Reagents
Code Description Quantity/test
Mi555-001 Standard (for Free & Total SO2) 50 mL
Mi555-002 Titrant (for Free & Total SO2)
Mi555-003 Alkaline Reagent (for Total SO2)5mL
Mi555-004 Acid Reagent (for Total SO2)5mL
Mi555-005 Acid Reagent (for Free SO2)5mL
Mi555-006 Stabilizer (for Free & Total SO2) 1 packet

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STARTUP
• Place the instrument on a flat table. Do not place the instrument on direct sun light.
• Connect the titrator to mains socket with ground connection and the correct voltage
and frequency. See the label on the instrument rear for this.
• Place the peristaltic pump tube on the pump. See the Pump Tube Replacement section
for the procedure.
• Remove the reagent bottle cap and place the bottle cap of the tubes set. 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).
• Turn the instrument ON using the power switch from the rear panel of the instrument
and wait until it displays dashes.

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PROBE FUNCTIONAL DESCRIPTIONPROBE FUNCTIONAL DESCRIPTION
PROBE FUNCTIONAL DESCRIPTIONPROBE FUNCTIONAL DESCRIPTION
PROBE FUNCTIONAL DESCRIPTION
GUIDE TO DISPLAY CODES
Purging mode message.
Main screen display with stirrer active.
Main screen display.
This screen appears for a few seconds each time the
instrument is turned ON.
This screen appears each time the meter enters pump
calibration mode. The meter is ready to start pump
calibration by pressing the START STOP button.
PUMP CALIBRATION MESSAGES
This screen appears while pump calibration is in progress.
Pressing CAL or START STOP button, the minititrator
returns to the main screen.
This screen appears for a few seconds before returning
to the main screen, when pump calibration is done.

Instruction Manual Mi455 FREE & TOTAL SULPHUR DIOXIDE Minititrator for wine analysis
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The used standard solution is wrong.
This error message appears when the input readings
(mV) exceed the input limits (0
y 1000mV).
This error message appears when the sample
concentration exceeds 400 ppm.
This screen appears each time a titration is running.
When the START STOP button is pressed the minititrator
returns to the main screen.
TITRATION MESSAGES
The titration result, expressed as concentration of sulphur
dioxide in ppm (mg/L), is displayed at the end of the titration
process. Press the START STOP button to return to the main
screen.
This error message appears when the input reading
exceeds the input limits (0 y 1000mV).
This screen appears when the sample concentration
exceeds 400 ppm.