Milwaukee MI490 User manual

INSTRUCTION MANUAL
SATISFACTION
GUARANTEED
MI490
Photometer for edible oils
Peroxide value

All rights are reserved. Reproduction in whole or in part is prohibited without the written
consent of the copyright owner, Milwaukee Instruments Inc., Rocky Mount, NC 27804 USA.
THANK YOU for choosing Milwaukee Instruments!
This instruction manual will provide you the necessary information for correct use
of the meter.

3
TABLE OF CONTENTS
1. FUNCTIONAL DESCRIPTION......................................................................................................................................4
2. GENERAL DESCRIPTION.............................................................................................................................................5
3. SPECIFICATIONS.............................................................................................................................................................6
4. GUIDE TO DISPLAY CODES........................................................................................................................................7
5. GENERAL TIPS FOR AN ACCURATE MEASUREMENT..................................................................................8
6. MEASUREMENT PROCEDURE.................................................................................................................................9
7. ERROR MESSAGES........................................................................................................................................................ 11
8. BATTERY REPLACEMENT.........................................................................................................................................12
9. ACCESSORIES ................................................................................................................................................................13
CERTIFICATION...................................................................................................................................................................14
RECOMMENDATION.........................................................................................................................................................14
WARRANTY...........................................................................................................................................................................14

4MI490 Photometer for edible oils
1. FUNCTIONAL DESCRIPTION
Display
A. BATTERY STATUS ICON
B. HOURGLASS ICON
C. LAMP STATUS INDICATOR
D. MEASURE STATUS
E. MEASUREMENT UNIT
F. MAIN DISPLAY
G. PARAMETER NUMBER INDICATOR
H. TIMER MODE INDICATOR
I. SECONDARY DISPLAY
Front Panel
A. LID
B. CUVET HOLDER
C. LIQUID CRYSTAL DISPLAY (LCD)
D. ON/OFF KEY, TO TURN THE METER
ON AND OFF
E. ZERO KEY, TO START THE ZERO
MEASUREMENT
F. READ KEY, TO START THE SAMPLE
MEASUREMENT
G. TIMER KEY, TO ACTIVATE THE
COUNTDOWN MODE TIMER
G
F
E
D
C
B
A

GENERAL DESCRIPTION 5
2. GENERAL DESCRIPTION
The MI490 is an auto-diagnostic portable microprocessor meter. It has an advanced
optical system based on a special tungsten lamp and a narrow band interference filter
that allows most accurate and repeatable readings. All instruments are factory calibrated.
The auto-diagnostic feature of this meter ensures always optimal measurement
conditions to ensure most precise readings. The light level is automatically adjusted each
time a zero-measurement is made, and the temperature of the lamp is controlled to avoid
overheating.
Significance of Use
Peroxides are the primary products of oil oxidation. Their identification gives useful
information about oil conservation and rancidity. MI490 allows fast and simple analyses
of peroxides in oil in accordance with the EC 2568/91 method.
Oil peroxides content
< 10 meq O2/kg excellent conservation
10-15 meq O2/kg good conservation
< 10 meq O2/kg refined oil
> 20 meq O2/kg rancid oil
This meter is supplied with:
yReagents for 10 tests (MI490A-0, MI490B-0)
yFour graduated 1 mL syringes
yTissue for wiping vials
yFour 1.5V AA batteries
yInstruction manual
yInstrument quality certificate
yWarranty card

6MI490 Photometer for edible oils
3. SPECIFICATIONS
Range 0.0 to 25.0 meq O2/kg
Resolution 0.5 meq O2/kg
Accuracy ±0.5 meq O2/kg
Light Source Tungsten lamp
Light Detector Silicon Photocell with narrow band interference filter @ 466 nm
Method
Adaptation of EC 2568/91 method and following amendments.
The reaction between sample and reagent causes a color
variation, proportional to the peroxide content expressed in
meq O2/kg.
Environment 0 to 50 °C (32 to 122 °F) ; max 95% RH non-condensing
Battery Type 4 x 1,5 volt AA batteries
Auto-Shut o After 15’ of non-use in measurement mode
Dimensions 225 x 85 x 80 mm (8.7 x 3.3 x 3.1”)
Weight 500 g (17,6 oz.)
Required Reagents
Code Description Quantity/test
MI490A-0 Peroxide Reagent A 1 vial
MI490B-0 Peroxide Reagent B 1 packet

GUIDE TO DISPLAY CODES 7
4. GUIDE TO DISPLAY CODES
This prompt appears for a few seconds each time the
instrument is turned ON.
This prompt indicates the battery capacity value.
Indicates that the instrument is in a ready state and waiting for
the next command (Timer or Zero).
After Timer is pressed, a blinking hourglass icon appears and
the display shows a 60 minutes countdown. At the end of the
countdown an acoustic signal alerts the user that the timer is
finished.
Indicates that the meter is performing a zero measurement.
The light intensity is automatically readjusted (auto-calibration
features) if necessary.
The instrument is zeroed and a measurement can be made.
Indicates that the meter is making a measurement.
Batteries voltage is getting low and the batteries need to be
replaced.
Indicates that the batteries are dead and must be replaced.
After this message appears, the instrument is switched o.
Change the batteries and restart the meter.

8MI490 Photometer for edible oils
5. GENERAL TIPS FOR AN ACCURATE MEASUREMENT
The instructions listed below should be carefully followed during testing to ensure best
accuracy.
yThe oicial method EC 2568/91 recommends to work at room temperature, between
15 and 25 °C.
yWhenever the vial is placed into the measurement
cell, it must be dry outside, and completely free of
fingerprints, oil or dirt. Wipe it thoroughly with Mi0004
(tissue for wiping cuvets, see chapter ACCESSORIES)
or a lint-free cloth prior to insertion.
yIn order to avoid reagent leaking and to obtain more accurate measurements, it is
recommended to close the cuvet very well with the cap.
yIn order to measure exactly 1 mL of oil:
a. Push the plunger completely into the syringe.
b. Insert the syringe in the oil and push the plunger
up and down twice to rinse and eliminate air
bubbles; then pull the plunger up until the lower
edge of the seal is exactly on the 0.0 mL mark.
c. Take out the syringe and clean the outside of
the syringe tip. Then, keeping the syringe in
vertical position above the vial, push the plunger
completely down into the syringe.
yProper use of the powder reagent packet:
a. use scissors to open the powder packet;
b. push the edges of the packet to form a spout;
c. pour out the content of the packet.

MEASUREMENT PROCEDURE 9
6. MEASUREMENT PROCEDURE
Read the entire instructions before using the kit.
yRemove the cap from a vial of MI490A-0 Peroxide reagent.
yUse the graduated syringe to add exactly 1 mL of oil. For a correct use of the syringe,
please see GENERAL TIPS FOR AN ACCURATE MEASUREMENT.
yAdd the sample to the vial and replace the cap.
yMix by inverting the vial twice.
yTurn on the meter by pressing the ON/OFF key.
When the LCD displays “---”, it is ready.
yPlace the vial into the instrument.
yPress the ZERO key and “----” will blink on the
display.
yAfter a few seconds the display will show “-0.0-”.
The meter is zeroed and ready for measurement.
Remove the vial.
yRemove the cap from the vial and add one packet
of MI490B-0 Peroxide reagent.
yReplace the cap and press TIMER to start the
countdown.
yMix vigorously for 1 minute.
yInsert the vial into the instrument and wait for
5minutes.
Note: 30 seconds before countdown finishes,
invert the vial twice.

10 MI490 Photometer for edible oils
yWhen the countdown finishes, the meter makes
the reading. If you have not used the TIMER
key, press READ to make the measure. In both
cases the display will show “----” during the
measurement.
yThe meter directly displays the peroxide value in meq O2/kg on the LCD.
Notes:
To convert the reading to mmol O2/kg multiply the reading by 0.5.
To convert the reading to mg O2/kg multiply the reading by 8.