Milestone MAXI-44 User manual

MAXI-44
User Manual
MA179
MILESTONE
HELPING
CHEMISTS

Milestone Srl MA179-004 –MAXI-44 –User Manual
GETTING STARTED GUIDE
1
Thank you for selecting our microwave system.
We are sure that you will be completely satisfied with the performance of
this new unit entering your laboratory. We invite you to read carefully this
user manual and to keep it in reach for convenient and fast consulting.
The person who will be using this unit should have received an
appropriate training from a Milestone trained technician. For any possible
clarification or any request for assistance please contact either our
Representative in your country:
or Milestone at the following address:
Milestone Srl
Via Fatebenefratelli, 1/5
24010 Sorisole (BG) Italy
Tel [phone]
Fax [phone]
Website www.milestonesrl.com
E-mail [e-mail]
Pubblication date (gg/mm/aaaa) 15/10/2021

Milestone Srl MA179-004 –MAXI-44 –User Manual
GETTING STARTED GUIDE
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1SAFETY INSTRUCTIONS......................................4
1.1 General Information.............................................................4
1.2 Safety in operations.............................................................4
1.3 Any unit manipulation allowed .............................................4
1.4 Maintenance and parts replacement....................................5
1.5 Customer support................................................................5
1.6 Other hints...........................................................................5
Working with accessories..............................................................................5
2SYSTEM DESCRIPTION........................................6
2.1 Overview .............................................................................6
2.2 Configurations .....................................................................6
There are four different types of MAXI rotor depending on the maximum
number and capacity of vessels:...................................................................6
2.3 Technical Specifications......................................................6
2.4 Temperature control ............................................................6
3VESSEL SYSTEM ..................................................7
3.1 Operations with MILESTONE high throughput rotors...........7
Weighing.......................................................................................................7
Chemicals addition........................................................................................8
3.2Vessel construction MAXI 44...............................................8
4OPERATIONS ........................................................9
4.1 Protection shield introduction...............................................9
4.2 Vessel closure and installation...........................................10
4.3 Rotor installation................................................................11
4.4 Rotor removal....................................................................12
4.5 Vessel removal..................................................................12
4.6 Vessel opening..................................................................13
5CARE AND MAINTENANCE INSTRUCTIONS....14

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5.1 General cleaning ...............................................................14
5.2 Care and maintenance of IR sensor ..................................14
5.3 IR-Sensor test instructions.................................................14
6CLEANING INSTRUCTIONS................................16
6.1 General..............................................................................16
6.2 Leaky cover.......................................................................16
6.3 Test of microwave absorption............................................16
6.4 Cleaning of the cover.........................................................16
6.5 Cleaning of protection shield..............................................17
6.6 Cleaning of PTFE vessel...................................................17
7APPENDIX............................................................18
7.1 Regular test (Accessories/vessels/rotors)..........................18
8MAXI-44 ROTOR TIPS AND TECHNIQUES........19
8.1 General working specifications..........................................19
8.2 MAXI-44 Vessels...............................................................19
8.3 Operating tips....................................................................20
8.4 Maintenance and Care ......................................................24

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1safety instructions
1.1 General Information
▪Please read carefully this operator manual before starting the system and follow its
prescriptions with the utmost care.
▪In case the system was delivered with additional accessories, also read carefully the
instruction manuals of such accessories.
▪Follow particularly the recommended instructions for Service and Maintenance.
▪This Operator Manual is part of the delivery, hence shall be always kept together with the
instrument on its working place.
▪It is imperative that every person operating this system has read and fully understood this
manual.
▪The non-observance of the instructions contained herein or improper use may involve
damages/injuries not covered by product liability!
▪The national ruling and international safety norms in working environment shall in any case
be observed under user’s responsibility.
▪It is also user’s responsibility to keep constantly updated all safety norms ruling in the
country or operation.
Information= indicates important information/recommendation for the user.
Attention = means that the warning non-observance may cause damages to unit
or properties.
Warning = means that the warning non-observance may cause injuries, even
severe, to people.
1.2 Safety in operations
▪The unit shall be operated only according to its intended purpose.
▪The unit shall only be operated within the power limits set by technical specifications.
▪The unit shall be operated exclusively by specially trained people.
▪All electrical parts shall always be protected from wet and humidity.
▪The unit shall be kept clean.
▪Basic rules of chemistry will always apply. The basic rules of chemistry are valid also for
chemicals handling. Working with chemicals, always take into account all safety measures
usually required (e.g. lab coat, protective gloves, protective glasses mask, exhausts hood,
etc.)
1.3 Any unit manipulation allowed
▪Constructive changes/modifications of the unit and its accessories are forbidden.

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1.4 Maintenance and parts replacement
▪In order to guarantee the good functioning of the unit and user’s safety, all replacement
parts shall be exclusively original supplied by the manufacturer. The original parts are
produced with particular attention to quality and manufactory production.
1.5 Customer support
▪The warranty certificate and qc report are included in the documents supplied with the
unit.
▪In case of unit reparation, please send us a service report with complete problem or
damage description.
▪For any question or spare parts order, please contact our representative in your country or
directly Milestone.
1.6 Other hints
▪Please take into account all the safety measures when filling in the vessels before the run
or when opening the vessel, once completed the run.
Don’t label the vessels. Discoloration may occur on protection shield with the
consequent damage.
Working with accessories
▪The complete vessel system must be treated with the utmost care and regularly tested. In
case of damage, the corresponding components must be replaced. Please pay particular
attention to the chapter “Care and maintenance instructions”.

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▪
2SYSTEM DESCRIPTION
2.1 Overview
The MAXI rotor (medium pressure rotor) contains up to 44 vessels for acid digestion of easy
to medium-difficult samples, such as soils, sludge, sediments, wastewater, food and feed,
pharmaceutical.
The MAXI-44 rotor in totally controlled by contact- less infrared sensor (T2) for
temperature control of each single vessel.
A high quality PTFE vessel serves as well as chemicals and heat resistant. In order to prevent
any deformation, the reaction vessel is protected by a PEEK protection cover. This high-quality
material keeps the inner vessel fit and ensures a longer lifecycle of vessel systems.
2.2 Configurations
There are four different types of MAXI rotor depending on the maximum number and capacity
of vessels:
Rotor
Positions
Volume
(Vessel capacity)
MAXI-44 (80 ML)
44
80 ml
MAXI-44 (100 ML)
44
100 ml
2.3 Technical Specifications
Rotor
Min volume*
Max volume
Recommanded
Working
Temperature
Max working
pressure
Recommanded
Max Holding
Time
MAXI-44
(80ML)
8 ml
50 ml
200°C
35 bar
30 minutes
MAXI-44
(100ML)
8 ml
50 ml
200°C
35 bar
30 minutes
* Since MAXI is totally controlled by external sensor (IR-TC), the minimum volume could be
less than 8 ml. It depends on several factors such as sample type, sample amount, acid mix.
Contact the Milestone application specialist for more informations.
When exceeding the specified limit values, you must consider that the parts are
subjected to increased stress or damage. If are used the maximum routine
conditions, a regular test of vessel systems has to be carried out. All maximum
values are reachable only with the suitable materials.
2.4 Temperature control
As mentioned above, MAXI-44 rotor is totally controlled by
contact-less infrared sensor (T2), which is positioned on the
right-hand side of the cavity. IR sensor is able to determine
the temperature of each single vessel oft he rotor by reading
the temperature of the external surface oft he safety shields.
Please, refer to Ethos UP/Ethos EASY User manual for detailed
info on the sensors.

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3VESSEL SYSTEM
3.1 Operations with MILESTONE high throughput rotors
When working with MILESTONE rotors, observe all safety indications and specifications. The
user must be familiar with the operations with vessel systems. In addition follow the operating
instructions reported in the microwave system user manual.
Weighing
In order to avoid erroneous changes among the vessels, the internal vessel should be
immediately closed and placed in the corresponding position of the numbered rotor.
Never label the vessels. The label color contaminates the protection shield and
diffuses into the vessel.
1. Place the cleaned vessel on the balance
2. Set the balance to zero (tare) and weigh the
sample.
3. Take note of the total weight or consider the
weight data on the terminal.
The weighing with the weighing paper and weighing boat is possible as option and
reduces e.g. the weighing errors due to electrostatic charge.

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Chemicals addition
Add the necessary chemicals by the dosing station
giving attention to wet every possible part of sample
left on the inner walls of the vessel.
E.g. by carbonates replacement, sample/chemicals foaming or spray can occur. Take
into account the necessary precautions and wear the suitable protection equipment,
such as protection glasses, gloves, working under fume hood etc.
When dealing with digestions, it normally makes sense to let the samples react 5 up to 10
minutes before closing the vessels. Before vessels closure, the sample must be well mixed with
the acid, otherwise it could result in severe partial reactions. For this purpose there are several
options: magnetic stirring, stirring bar etc. When handling samples with consequent gas
development, a cover is placed on the vessel, in order to avoid spray losses.
3.2 Vessel construction MAXI 44
Vessel 80 ml / 100ml
Cover
Vessel cover with thread

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4OPERATIONS
4.1 Protection shield introduction
Shift the silicon protection ring on the lower side
of the protection shield.
The protection ring must be located on the
opposite of the tapered side.
Place the protection shield in the notch on the
bottom plate. The taper should be placed with
the face up.
Once introduced all the protection shields, place
the centering plate and screw it with its four
screws. Be careful that the marks (black points)
coincide.

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Place the lifting plate on the rotor and screw it
with its three screw nuts.
The rotor position 1 and the black mark should
coincide.
4.2 Vessel closure and installation
No special closure tool is required to close the vessel, but you can perform it by hands.
Place the little cover on the vessel. The pin
on the cover must face up.
Screw the thread cover on the vessel.
Place the closed vessel in the rotor.
In case of free rotor positions, the corresponding protection shields remain in the
rotor.
For a better performance of the Infrared Temperature Control (IR-TC)
sensor, in case of free rotor positions, vessels must be distribuited as
homogeneous as possible and firstly on the outer circle positions.

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4.3 Rotor installation
In the rotor bottom side there is the driving
plate. The inner ring has a square edge on one
side.
This edge and the black mark are always located
in rotor position 1.
The peek adapter in the unit has a flattered level
too.
Introduce the rotor in the unit, so that both
leveled sides (rotor and peek adapter) matches
one with the other.
When the rotor is locked in position, turn it not by
using hands, otherwise you could damage the adapter,
but use the function Rotor (see software description.
The rotary plate turns so long as the function exhaust
is active).
IR measuring settings can be found in the software manual of the terminal.

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For a better performance of the Infrared Temperature Control (IR-TC)
sensor, the “TWIST” function must be deactivated (See the software
manual).
4.4 Rotor removal
Remove the rotor by lightly raising it.
4.5 Vessel removal
For an easy removal of vessels (one by one) from rotor body, use the MAXI-44 Support
(LC000365).
Fix the MAXI-44 support to your ETHOS unit as
shown in the pictures
Move the rotor out of the cavity.
Remove the vessels one by one.
For a fast removal of all vessels from rotor body, see the following instructions

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Untighten the screw nut on the top plate.
Drag out the top plate by the handle with the
vessels facing up.
Place the lifting plate with the vessels on the
samples holder.
4.6 Vessel opening
The vessel system must be cooled down, before its opening. In general a temperature of ca.
50°C is recommended as reference value. But this depends on the boiling point of the
chemicals used and cannot be considered as limit value. Before opening the vessel, the
pressure has to be released, in order to avoid any fast over-pressure release.

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5CARE AND MAINTENANCE INSTRUCTIONS
▪In case of irregular rotor movement, check the bullets on the bottom side of the rotor body.
If they can’t be easily moved in the guide, dust or dirt may be present between the bullets
and can be removed by using alcohol. The bullets can be sprayed with some lubricant and
releasing agent on the PTFE base.
5.1 General cleaning
▪All rotors should be regularly checked and cleaned. Don’t use any organic solvent to clean
the plastic parts (e.g. acetone attacks PSU). The rotors should be cleaned from acids or
other residues after each run, e.g. with diluted alcohol.
▪Water or acid residues should be thoroughly dried before use in the microwave, because
they are heated in the microwave and can lead to damages. This concerns particularly
water or acid residues between the PTFE inner vessel and the protection shield. For any
question, contact Milestone or our representative in your country.
▪In case acids, especially high boiling acids (e.g. sulfuric acid), reach the rotor bottom side,
the whole rotor must be washed with plenty of water and then completely dried (no water
residue should be present at the moment of microwave irradiation).
5.2 Care and maintenance of IR sensor
The IR sensor function must be weekly tested following the instructions in
chapter “IR sensor test instructions” (see the following chapter).
In case the test is not passed, the IR sensor must be cleaned. Then the function
test must be repeated. A ventilated special sensor can be used for extreme
cases, since it considerably reduces or prevents contamination.
To ensure a correct measuring by the IR sensor, the sensor (this means the measuring lens and
the sensor lens therein) must be cleaned from impurities by using a wet bud and alcohol. In
case of contamination or unusual/abnormal program, the IR sensor must be cleaned after each
run.
The IR sensor lens can be chemically attacked by vapors such as HF. The consequence due to
sensor contamination or corrosion is too low measuring values.
In case chemicals reach the sample chamber, the IR sensor function must be absolutely tested
in accordance with test prescription.
5.3 IR-Sensor test instructions
1. The IR sensor lens is located on the right side in Start and ETHOS unit. Fill in e.g. 300ml
water in a beaker. The water level must be located over the height of the IR lens.
Before starting the test, remove the body plate, since it can be deformed by the heat of the
beaker.
2. Place the beaker before the IR lens.
3. Start the following program.
00:05:00
800 Watt
all parameter like T2 etc. on 0 (deactivated)

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It’s necessary to work with stirrer or similar accessories, to avoid boiling delay.
Otherwise the test is not meaningful.
In the range of water boiling point, the curve decreases despite the continued
irradiated power (see the below example). The sensor must display at least 145°C
with control via IR control. An additional regular test with a suitable thermometer
with open sample chamber (microwave off!) is advantageous.
Example of IR sensor test

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6CLEANING INSTRUCTIONS
6.1 General
PTFE vessel and cover, due to their extensive use, accumulate e.g. NOx, that the
microwave properties are considerably changed. This mainly occurs in case of
digestion temperatures over 200°C and is accelerated by even high temperatures
and high pressure.
6.2 Leaky cover
If a cover is leaky, e.g. due to deformation, it must be replaced.
6.3 Test of microwave absorption
Below are described the instructions to be followed to test, if PTFE vessel and
cover absorb excessively the microwaves.
1. Place the dried rotor body in the microwave and distribute the parts to be tested.
For this purpose you can use the vessels without protection shield or cover.
The parts to be tested must be washed and dried, so that no acid residues may be
located on the parts.
2. Start the following microwave program, depending on the vessels number.
▪45 seconds 600 W (for 10 up to 16 vessels)
▪45 seconds 450 W (for 6 or less vessels)
3. Once concluded the run, check immediately the temperature with the hands (it would be
better with thin gloves) or possibly via the IR control. A rough evaluation of the
temperature, such as cold/slightly warm/really warm/hot is enough.
Danger of burns! Each single vessel can be very hot.
In a microwave program should be generally
used, whenever possible, as more similar
vessels as possible. Vessels warmer than the
hand temperatures (37°C) should be
cleaned.
Especially in case of hot vessels, a NOxload
can be noted on a vessel.
The discolored container has been particularly affected by a high weighing. This
can be significantly reduced by following an optimized application.
6.4 Cleaning of the cover
The cover should be cleaned only with clear water.

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6.5 Cleaning of protection shield
The protection shield should be cleaned only with clear water and should be dried before the
use.
6.6 Cleaning of PTFE vessel
Graphite or grease residues on all PTFE vessels can be cleaned with organic solvents (e.g.
alcohol). It is recommended to clean the surface with a paper towel. The vessels can be
cleaned in a laboratory dishwasher.
An almost complete decontamination can be reached by a cleaning procedure with HNO365 %.
A maximum cleaning temperature of 180°C is enough for this purpose. The steaming out of
vessels with Milestone TraceCLEAN is easier and more efficient.
Rinse thoroughly the vessels previously cleaned with deionized water and place them at least
for 3 hours in a drying oven (if possible ventilated) at 160°C maximum 180°C.
▪PTFE vessels should be placed with the opening facing up
▪PTFE covers should be placed with the bottom side facing up
After vessel cooling to room temperature, the test for microwave absorption
should be repeated. Should the vessels significantly absorb microwave, this would
mean they are strongly contaminated and the cleaning should be repeated.

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7APPENDIX
7.1 Regular test (Accessories/vessels/rotors)
Customer address:
Company:
Department:
Contact:
Address:
Post Code, place:
Tel./FAX:
E-mail:
VESSEL SYSTEMS CONDITIONS
Vessel type
p/n
Status
ROTOR BODY CONDITIONS
Rotor type
p/n
Status
UNIT/ACCESSORIES GENERAL CONDITIONS