Hydro user manual. Malvern Instruments Limited

Transcription

1 Hydro 2000 µp Malvern Instruments Limited Printed in England MRK user manual Enigma Business Park Grovewood Road, Malvern Worcs, WR14 1XZ, U.K. Tel: +44 (0) Fax: +44 (0) I N S T R U M E N T S

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3 Hydro 2000µP User Manual MAN0389 Issue 1.0 March 2007

4 Malvern Instruments Ltd Malvern Instruments makes every effort to ensure that this document is correct. However, due to Malvern Instruments policy of continual product development we are unable to guarantee the accuracy of this, or any other document after the date of publication. We therefore disclaim all liability for any changes, errors or omissions after the date of publication. No reproduction or transmission of any part of this publication is allowed without the express written permission of Malvern Instruments Ltd. Head office: Malvern Instruments Ltd. Enigma Business Park, Grovewood Road, Malvern, Worcestershire WR14 1XZ United Kingdom. Tel + [44] (0) Fax + [44] (0) Windows 2000 and XP are registered trademarks of the Microsoft Corporation. Tygon is a registered trademark of Norton Co. Perlast is a registered trademark of Precision Polymer Engineering. Printed in England

5 Table of Contents Part 1 - Operator s Guide Introduction to this manual Introduction Access to the dispersion unit Assumed information Where to get help Hardware features Introduction What the dispersion unit does How the dispersion unit is controlled How the dispersion unit works Hardware features Software features Introduction Making a measurement Manually controlling the dispersion unit Writing an SOP for the dispersion unit Making a measurement Introduction Measurement guidelines Instrument preparation Anaerobic fill Measuring new samples Changing cell holder position Introduction Hydro 2000µP Page i

6 Table of Contents Hydro 2000µP Part 2 - Appendices Specification Specification A-1 Chemical compatibility Introduction B-1 Regulatory statements CE Declaration of Conformity C-2 Index Page ii MAN 0389

7 Part 1 - Operator s Guide

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9 1 Introduction to this manual Introduction This manual describes the operation of the Micro Precision Hydro 2000µP sample dispersion unit, one of the following: Instrument Hydro 2000µP (with ultrasonics) Hydro 2000µP (without ultrasonics) Model number AWA2003 AWA2004 This manual is a supplement to the following manuals: Mastersizer 2000 User Manual (termed the main User Manual ). Mastersizer 2000 Essentials Manual (termed the Essentials Manual ). This dispersion unit manual focuses on some specific issues of the dispersion unit that are not covered by the above manuals. It aims to: Describe what the dispersion unit is and explain in simple terms how it works. Identify the physical features of the dispersion unit. Describe the software and explain how to use the dispersion unit to make a measurement on the system. Warning! The dispersion unit or the samples to be measured may be hazardous if misused. Users must read the Health and Safety information in the Essentials Manual before operating the system. We recommend that users who have never operated a Malvern particle analyser read this manual fully before starting the first measurement. Those who are more familiar with particle size analysers may wish to jump straight to Chapter 4 of the main User Manual which gives details on making measure- Hydro 2000µP Page 1-1

10 1 Chapter 1 Introduction to this manual ments. However, the importance of sample preparation before measurement cannot be overstated so we recommend reading the chapter on sample preparation (Chapter 8 of the main User Manual) as a priority. Access to the dispersion unit Within this manual, reference is made to the various people who will have access to the dispersion unit. The following is a list of these people and their responsibilities: Malvern personnel Malvern personnel (service engineers, representatives, etc.) have full access to the dispersion unit and are authorised to perform all service procedures that may require the removal of the covers. Supervisor The supervisor is the person responsible for the management/safety of the dispersion unit and of its operation. The supervisor is responsible for the training of the operators. The supervisor can perform all user maintenance routines identified in Chapter 4 of the Essentials Manual. Warning! The supervisor/operator must never remove the covers of the instrument or dispersion unit. Removal of the covers by unauthorised personnel will invalidate the warranty of the dispersion unit. Operator An operator is a person trained in the use of the dispersion unit. The operator can perform all user maintenance routines identified in Chapter 4 of the Essentials Manual. Warning! Failure to follow this guideline could result in exposure to hazardous voltages. Page 1-2 MAN 0389

11 Introduction to this manual Chapter 1 Assumed information Naming convention Within this manual: The Mastersizer 2000 optical bench is referred to as the optical bench or the instrument. The Hydro 2000µP is referred to in full or as the dispersion unit. The combination of the optical bench, one or more dispersion units and the computer is referred to as the system. Menu commands Menu commands from the Malvern software are referred to in the form main menu-menu item. As an example, the command Configure-New SOP refers to selecting the New SOP item in the Configure menu. The same rules apply for sub-menus of sub-menus, so that Tools-Options-Instrument Port refers to the Instrument Port item in the Options sub-menu, which itself is a sub-menu of the Tools menu. Menu commands are always shown in bold text. Where to get help Full details on where and how to obtain help can be found in Chapter 1 of the Mastersizer 2000 User Manual. The Essentials Manual gives information on the following: Site requirements. Health and Safety. Maintenance. Installation (in case the system has to be moved after its initial installation by Malvern Instruments personnel). Hydro 2000µP Page 1-3

12 Chapter 1 Introduction to this manual Page 1-4 MAN 0389

13 2 Hardware features Introduction This chapter gives a simple overview of the dispersion unit. All key aspects of the dispersion unit s operation are explained in very simple terms. This chapter covers: What the dispersion unit does. How the dispersion unit is controlled. How the dispersion unit works. The hardware features in detail. Hydro 2000µP Page 2-1

14 2 Chapter 2 What the dispersion unit does Hardware features The sole purpose of any sample dispersion unit is to prepare the sample then deliver it to the measurement zone of the optical bench so that it can be measured. The Hydro 2000µP allows the Mastersizer to be used for particle-in-liquid particle sizing and has been specifically designed so that only small amounts of sample and suspending liquids (dispersants) are required. The small volume of the Hydro 2000µP is ideal when using solvent dispersants or when samples and dispersants are either expensive or hazardous. The materials used in the manufacture of the dispersion unit maximise the range of samples which can be measured. Other features of the dispersion unit include: Variable speed pump allows a wide range of particle sizes and densities to be suspended and circulated. Ultrasonic system (optional) allows particle agglomerates to be dispersed and assists in removing bubbles from the system. Warning! When using solvents, especially those with low ignition points, minimise the use of ultrasonics. There is a remote possibility that localised heating caused by the ultrasonic action may cause an explosive reaction. Check the Material Safety Data Sheets for all substances used. Temperature sensing an internal sensor monitors the temperature of the dispersant. The software can be configured so that measurements are only made between user specified temperature limits. This can be used to ensure that the instrument can only be used when it has reached the correct temperature. How the dispersion unit is controlled The dispersion unit is controlled using a single software dialogue with sliders for the pump speed and ultrasonic power (Chapter 3 has details). The dialogue also has pump pause, drain valve and Anaerobic fill buttons. When controlled through a Standard Operating Procedure (SOP), the software tells the user what value to set for each parameter. Page 2-2 MAN 0389

15 Hardware features Chapter 2 How the dispersion unit works The dispersion unit looks like this: The dispersion unit comprises two main units: The control unit which contains most of the control electronics. The cell unit which contains the cell, the sample well, pump, ultrasonic probe (optional) and the drain facilities. The dispersant is injected into the cell via the dispersant inlet port using a syringe. Once preliminary measurements ( backgrounds ) are made, the sample to be measured is added to the well. The pump agitates the dispersant to ensure that the sample does not settle out and continually circulates the sample through the cell and then back to the well. Within the cell, the dispersant and sample flow between two glass windows. The windows are precisely mounted within the measurement zone of the optical bench where a laser is passed through the sample/dispersant mixture. The particles within the sample scatter the laser light. This scattered laser light is measured by the optical bench and used to calculate the particle size distribution of the sample. ill 5473 Hydro 2000µP Page 2-3

16 Chapter 2 Hardware features The optional ultrasonic probe can be used to break up particle agglomerates and help to remove bubbles from the system. Once the sample has been measured, an internal drain valve is operated and the dispersant and sample are drained to an external beaker. The lid for the well should always be fitted during a measurement. The lid is locked in place by rotating the locking lever. All functions of the dispersion unit are controlled using the Malvern software. Hardware features This section describes the hardware in detail. Main system components The diagram below shows a typical installation for the Hydro 2000µP. Its main components are identified. These components are examined in more detail later in this section Power supply The external DC Power Supply Unit (PSU) supplies all power requirements to the dispersion unit. ill 5407 Page 2-4 MAN 0389

17 Hardware features Chapter 2 Warning! The PSU used on the Hydro 2000µP is not designed for operation in wet conditions. Do not place it in areas that are prone to spillages. Warning! Only use the power supply and cables supplied by Malvern Instruments. Control unit The control unit contains most of the control electronics for the dispersion unit. Power and communications cables are connected to the control unit. A control cable is connected from the front of the control unit to the front of the cell unit. Cell unit The cell unit contains the cell, well, pump and drain facilities. The cell unit is designed to circulate the sample and dispersant mixture and pass it through the analysing laser beam of the optical bench. Sample well The well in the cell unit is where sample to be measured is added. The sample well and connecting pipes have a capacity of less than 20ml. Dispersant input/syringe The dispersant for suspending the sample and flushing the system is injected into this port using a syringe. Always use a syringe with a maximum capacity of 20 to 25ml. Drain beaker Once the measurement is complete (or during a flush routine to clean the system) an internal drain valve can be operated. The contents of the cell will drain through the drain port into the drain beaker. If the end of the drain pipe is under the surface of the waste liquid, the back pressure created may prevent the cell from draining correctly. Typically ensure that the end of the tube is approximately 3cm below the rim of the beaker (slide the beaker holder until the correct length is achieved). Hydro 2000µP Page 2-5

18 Chapter 2 Hardware features ill 5643 Warning! If using hazardous dispersants or samples, do not allow the beaker to become over-full. If dispersants or samples are noxious, the instrument should ideally be used in a fume cupboard. Drain beaker holder The drain beaker may hold hazardous samples and dispersants. The drain beaker holder secures the drain beaker to prevent it from being accidentally knocked over when the cell unit is removed from the optical bench. We recommend that the beaker holder is always used. Cell unit holder The cell unit holder is a parking area for the cell when it is not in use. This is particularly useful when more than one dispersion unit is in use. It allows the cell to be removed and stored without the need to disconnect it from the dispersion unit. When the cell is parked for a short period make sure that the cell is full of dispersant. If it is to be parked for longer periods, the unit should be drained and the cell windows dried. The Essentials manual describes these procedures. Well lid The well lid is used to reduce the escape of hazardous fumes when measuring using hazardous samples and dispersants. It also reduces the risk of accidental splashing from the well. Always use the well lid when making measurements or moving the cell unit. Always lock the lid into place with the lid locking lever. Lid locking lever The lid locking lever is used to lock the well lid in place when measurements are taking place. Page 2-6 MAN 0389

19 Hardware features Chapter 2 Dispersant valve The dispersant valve is used to prevent sample or dispersant leaking when the dispersant input syringe is removed. Two types of valve are available: Aqueous valve this is disposable and can be used with non aggressive dispersants such as water. The valve is easily identifiable as it is made of transparent, purple plastic. Non-aqueous valve suitable for use with a large range of chemically aggressive dispersants. The non-aqueous valve is white and has a tap on its side. Replacement valves are available from a Malvern representative. Controller unit This section examines the controller unit in more detail. As stated above, the controller unit contains most of the control electronics for the dispersion unit. Rear panel The rear panel of the controller unit is shown below and its main features identified. DRAIN OPEN/CLOSED 4 CAUTION Flash tests can permanently damage this equipment WARNING: To prevent electric shock do not remove screws. No user serviceable parts inside. Refer servicing to Malvern trained service personnel. DC IN 24V 2.9A 1 ACCESSORY COMMS IN OUT 2 3 DC power input Power input from the external power supply. ill 5409 Hydro 2000µP Page 2-7

20 Chapter 2 Hardware features Warning! The PSU is not designed for operation in wet conditions. Do not place it in areas prone to spillages. Warning! Only use the PSU and cables supplied by Malvern Instruments. Accessory comms in connector The communications cable from the optical bench or from another dispersion unit connects here. Accessory comms out connector If more than one dispersion unit is connected to the system and this is the first dispersion unit in line, a communication cable will be connected from this connector to the Accessory comms - in connector on the second dispersion unit. Caution! The termination plug supplied with the optical bench must be fitted here if this is the only dispersion unit connected or it is the last dispersion unit in the line. Manual drain The manual drain button can be pressed to drain the well. Users may wish to do this if, for example, they need to drain the dispersion unit without having to start the control software. Pressing the button once (for about half a second) will open the drain valve. Pressing the button a second time will close the drain valve. If the drain valve is left open for more than 15 minutes it will automatically close. Page 2-8 MAN 0389

21 Hardware features Chapter 2 Front panel The front panel of the controller unit is shown below and its main features identified. 1 2 CONTROL ULTRASOUND 3 4 HYDRO Status indicator The status indicator illuminates in one of three colours when the dispersion unit is powered up: Green if the dispersion unit is functioning correctly and the cell unit has been loaded into the optical bench (i.e. the dispersion unit is active ). Amber if the dispersion unit is functioning correctly but the cell has not been loaded into the optical bench (i.e. the dispersion unit is at standby and is parked in the cell unit holder). Red if the software has detected a error. If an error message does not appear on the screen, selecting Configure-Accessories displays the accessory control dialogue which should show the type of error. Power on/off This is the main power switch for the dispersion unit. Control cable The control cable carries all power and communication signals between the control unit and the cell unit (with the exception of ultrasonics). ill 5410 Hydro 2000µP Page 2-9

22 Chapter 2 Hardware features Ultrasonic control cable (optional) If the ultrasonic option is fitted, this cable will carry power and control signals for the ultrasonic probe between the control unit and the cell unit. Warning! The Ultrasonic control cable carries high voltages. Under normal operating procedures this is perfectly safe. Inspect the cable at regular intervals for any sign of damage. Never operate the equipment if the cable is damaged. Cell unit The cell unit is shown below with its main features identified Well cone The well cone is where the sample is added to the cell unit. Typically, dispersant is added by filling the well to within 1 to 2mm of the top of the well. Perform an ill 5495 Page 2-10 MAN 0389

23 Hardware features Chapter 2 anaerobic fill (to remove bubbles) and then remove dispersant directly from the well using a pipette so that the well is about a quarter full. Overflow If the well is overfilled any excess is directed to the drain port via the overflow. Control cable The control cable carries all power and communication signals between the control unit and the cell unit (with the exception of ultrasonics). Ultrasonic control cable (optional) If the ultrasonic option is fitted this cable carries control signals for the ultrasonic transducer between the control unit and the cell unit. Dispersant inlet port The dispersant for suspending the sample and flushing the system is injected into this port using a syringe. To avoid introducing bubbles into the system, use a slow, steady pressure when injecting the dispersant; see Chapter 2 for details. Warning! Always consult the Materials Safety Data Sheet for any handling and safety information for all dispersants used. Only use syringes with a maximum capacity of 20-25ml. The dispersant for suspending the sample and flushing the system is injected into this port using a syringe. To avoid introducing bubbles into the system, use a slow, steady pressure when injecting the dispersant; see Chapter 2 for details. Fill the well until dispersant is visible within the well cone. Dispersant valve The dispersant valve must be used on the dispersant inlet to prevent sample/dispersant from leaking when the dispersant syringe is removed. Two types of valve are available, as described earlier. Replacement valves are available from a Malvern representative. Drain port When the drain valve is operated, the contents of the cell will flow out through this port. A tube will guide the contents to a waste beaker. Always ensure that the waste beaker has enough capacity before draining the cell. Well lid The well lid should always be in place when making measurements (except when adding sample). The lid reduces the amount of vapour released when using solvents as a dispersant. It also stops dispersant from welling up and stops air being sucked in. Hydro 2000µP Page 2-11

24 Chapter 2 Hardware features Additionally, when measurements are performed using solvents, users may occasionally find that the background levels are very high. This is due to temperature gradients within the solvent. The normal cure is to wait for several minutes for thermal equilibration, or even to warm the solvent beforehand. In many cases, a much simpler and quicker solution is to ensure that the lid is in place. Lid locking lever The lid locking lever is used to lock the well lid into place during measurements. Cell windows The cell windows allow the analyser beam of the optical bench to pass through the cell and hence the particle field. The cell windows can be removed to allow cleaning or replacement. Caution! The cell windows are delicate and should be treated with caution; refer to the Essentials Manual for details on cleaning the windows. Window ring lock screws The windows can be removed for cleaning. The window ring lock screws can be loosened to allow the window ring and window to be removed; refer to the Essentials Manual for details. Page 2-12 MAN 0389

25 3 Software features Introduction This chapter describes all the physical features of the dispersion unit. It covers: Making a measurement the basics of making a measurement using the dispersion unit. Manually controlling the dispersion unit. Writing a Standard Operating Procedure (SOP) for the dispersion unit. Software features the features of the Malvern software that are specific to the dispersion unit. Hydro 2000µP Page 3-1

26 3 Chapter 3 Making a measurement Software features The dispersion unit can either be controlled manually or automatically by running a Standard Operating Procedure (SOP). Making a measurement is fully documented in Chapter 4 of the main User manual. The system automatically detects which dispersion unit and cell is connected. If more than one dispersion unit is connected, the system detects all dispersion units connected, but only the dispersion unit that has its cell installed on the optical bench will be active. Manually controlling the dispersion unit To control the dispersion unit manually either select Configure-Accessory or, when making a manual measurement, click the Accessory button in the Measurement Display window. This accessory control dialogue appears: ill 7776 This dialogue is specific to the Hydro 2000µP. It has separate Control and Errors tabs. Use it to alter the pump speed and (optionally) the ultrasonic power by moving the relevant slider bar. Page 3-2 MAN 0389

27 Software features Chapter 3 It features the following: Pump Speed control The speed of the pump (which controls the speed at which the sample is circulated) is altered by moving the slider. Use the up and down arrows under the slider for fine adjustment of the pump speed. Ultrasound control (optional) Warning! When using solvents, especially those with low ignition points, minimise the use of ultrasonics. There is a remote possibility that localised heating caused by the ultrasonic action may cause an explosive reaction. Check the Material Safety Data Sheets for all substances used. The power of the ultrasonic probe is altered by moving the slider. Use the up and down arrows under the slider for fine adjustment of the ultrasonic power. Dispersant temperature The temperature of the dispersant within the cell is continually monitored and displayed here. Temperature monitoring can be used in conjunction with the Sampler Settings dialogue to limit the range of temperatures at which measurements can be made. Pause Pump button Pressing the Pause Pump button stops the pump motor. Pressing the button a second time restarts the pump. The indicator to the right of the button shows red if the pump is paused, and green when the pump is running. i Note If having difficulty with bubbles in the system, they can often be removed by turning the pump on and off in quick succession using Pause Pump. Drain Valve button Pressing the Drain Valve button will open the drain valve, allowing the contents of the cell to be emptied into the waste beaker. The indicator to the right of the button will show red if the drain is open and green when the drain is closed. Anaerobic fill button Due to the small volume of the Hydro 2000µP and associated problems of removing bubbles from the system, a special fill sequence called Anaerobic fill can be used. Chapter 4 gives details. Hydro 2000µP Page 3-3

28 Chapter 3 Software features Error indicators The following indicators on the Errors tab illuminate if an error condition has been detected. Connection box disconnected shows red if the control cable from the control unit to the cell unit is not connected. Dispersant Temperature Probe shows red if the temperature is outside the range 10 C - 35 C or there is an internal error with the temperature sensor. Contact a Malvern representative if this error condition persists. Drain Valve illuminates if the drain valve has failed to drive (i.e. it has stuck open or closed). This may be caused by leaving a sample in the cell for long periods - this may have set and bonded the drain valve. Never leave the sample in the cell for long periods - always flush the cell with clean dispersant. Contact a Malvern representative if this error indicator illuminates. Pump illuminates if there is a problem with the pump controller electronics Pump over temperature illuminates if the pump is over its operating temperature range. The pump will stop until its temperature returns to the operating range. The pump will typically overheat if the sample dispersant is too viscous or the sample material is too large, causing jamming. Pump speed control illuminates if the difference between the speed demanded and the actual speed exceeds 500rpm for over 10 seconds. Ultrasound illuminates if there is an error with the ultrasound control electronics. Ultrasound displacement illuminates if the current supplied to drive the ultrasound probe is too high. Ultrasound timeout illuminates if the ultrasound is left on for over 15 minutes. Status indicators These indicators give the current status of the pump and ultrasonic probe. If this indicator shows green then the pump or ultrasonic probe are currently in use. If the Ultrasonics indicator is greyed out then the unit does not have the ultrasonic option installed. Page 3-4 MAN 0389

29 Software features Chapter 3 Writing an SOP for the dispersion unit A Standard Operating Procedure (SOP) can be configured to control all settings for the dispersion unit automatically. When an SOP is run the software (depending on how the SOP is set up) automatically runs a measurement, giving instructions to the operator such as when to add dispersant, sample, etc. The SOP even reports if the wrong cell unit is fitted. The SOP wizard is described in full in the main User Manual. Here we just describe those dialogues which are specific to the Hydro 2000µP. These are the Sampler Selection and Sampler Settings dialogues. Sampler Selection dialogue The Sampler Selection dialogue is shown below: 1 2 It features: ill 7774 Sample handling unit list Select the dispersion unit to be used from the drop down list. All dispersion units available will be listed, even those that are not attached to the system. This allows an SOP to be written remotely from the system. All systems the SOP is distributed to must have the dispersion unit connected. The system allows up to two of each dispersion unit to be connected to the optical bench. In this situation, the dispersion units will be identified as unit A and B - in Hydro 2000µP Page 3-5

30 Chapter 3 Software features the case of this dispersion unit there would be an entry for Hydro 2000µP (A) and Hydro 2000µP (B). If using just one dispersion unit, select the A option. Sample handling unit options This dispersion unit is supplied in two versions, with ultrasonics and without ultrasonics. Use this pull down list to select the model in use. If the user tries to run an SOP that has been defined for an dispersion unit with ultrasonics on an dispersion unit without that option, a message is displayed, telling them to connect the correct dispersion unit. Sampler Settings dialogue The Sampler Settings dialogue is shown below: Its features are: ill 7775 Pump speed The pump speed is altered by moving the slider or entering the required speed in the RPM box to the right of the slider. Selecting the Advanced button displays the Vari-flow options. Some materials such as metal flakes have been found to form structures when they are circulated through the cell at normal pump speeds. These structures give rise to a secondary diffraction pattern that is incorrectly interpreted as a small peak at 1000 microns. Vari-flow allows these materials to be dispersed in the well in the normal way and then the pump is briefly turned off or reduced before measurement of the sample. When the pump is turned off, the structures in the sample are randomised and the Page 3-6 MAN 0389

31 Software features Chapter 3 measurement can be made without the occurrence of the secondary diffraction pattern. When the flake material is suspended in a volatile solvent, such as white spirit, variflow is even more useful since it assists the rapid thermal stabilisation of the optics. When the sample well is filled with fresh solvent, very high backgrounds can often be observed. These arise from thermal gradients in the solvent causing steering of the laser beam onto the inner rings of the internal detector. As the temperature equilibrates, the background will fall to normal levels (80-100) and the measurement can proceed. Pausing the pump after the solvent has had a chance to thoroughly disperse through the system will accelerate the fall of the background to normal levels. Ultrasonics Warning! When using solvents, especially those with low ignition points, minimise the use of ultrasonics. There is a remote possibility that localised heating caused by the ultrasonic action may cause an explosive reaction. Check the Material Safety Data Sheets for all substances used. The ultrasonics radio buttons enable the ultrasonic transducer. The options are: None no ultrasound. Continuous (from sample addition) ultrasound is activated after sample is added and will run continuously. Pre-measurement ultrasound is activated for a set time prior to measurement. For pre-measurement mode, type in the required duration in seconds in the Duration box. Continuous (from start) ultrasound is active throughout the measurement. Ultrasound will start after the electrical background is complete. The stabilising period will add a delay between the electrical background and the optical alignment. During this delay ultrasound will be active to allow bubbles to be driven from the dispersant. Either click and drag the slider bar to set the level, or type the exact level required in the box to the right of the slider bar. Determine the optimum ultrasound level and duration using manual control, ensuring that the lowest setting giving satisfactory dispersion is obtained. Record the settings and transfer these to the SOP in the Sampler Settings dialogue using the slider controls. Hydro 2000µP Page 3-7

32 Chapter 3 Software features Pre-Measurement Delay A pre-measurement delay can be added before the measurement to allow thermal equilibration to occur after ultrasound has been applied. If this is not done the analysis may show the presence of large particles which are not in the sample. This is caused by the refractive index differences observed in the sample cell when the dispersant is not equilibrated. Choose a delay sufficiently long enough for adequate thermal equilibration to occur. To set the delay, highlight either the minutes or seconds in the entry box, then use the selection arrows to alter the time; alternatively the time can be typed in. A delay of between 0 and minutes can be chosen. Temperature Monitoring It is possible to monitor the temperature of the sample and dispersant and to set the software to only make measurements between specified limits. Temperature monitoring is enabled by selecting the Allow measurements only. check box. The options are: Lower/upper limit this section specifies the temperature range within which the sample/dispersant must be for the measurement to start. This limit must be in the range of 10 to 35 C. Stabilising temperature the time for which the temperature must be stable before the measurement proceeds. Time-out period the measurement will be abandoned if the temperature is not stabilised within this time period. Page 3-8 MAN 0389

33 4 Making a measurement Introduction This chapter describes how to make a measurement using the Hydro 2000µP. It covers: Measurement guidelines. Instrument preparation. Anaerobic fill. Measuring new samples. Hydro 2000µP Page 4-1

34 4 Chapter 4 Measurement guidelines Making a measurement The Hydro 2000µP uses very low volumes (approximately 20ml) of dispersant and sample. When using such small quantities, take the following precautions when making a measurement: Minimise the amount of sample lost during sample preparation, or through sample adhering to the sides of the well. Cleanliness of the system is critical: very small amounts of cross-contamination can bias the results. Manage the pump speed to prevent the introduction of bubbles, while also ensuring that the sample is kept in suspension. This is true for all wet sample dispersion units but particularly important with the small dispersant volumes of the Hydro 2000µP. The basic procedure Add dispersant to the well by injecting the requested dispersant through the inlet port. Inject the dispersant slowly until the level of the dispersant is within 1 to 2mm of the internal rim of the well. Because the stirring and the circulation of the sample is carried out in the chamber below the well cone, keep the level of dispersant in the well low. If sample is seen adhering to the sides of the well cone, use a pipette to withdraw some of the dispersant from the well to rinse the sides of the well. Once the sample has been added, it is important to replace the well lid and lock it in place using the locking lever. Minimising sample loss Sample loss by adhesion To prevent sample adhering to the side of the sample well during sample addition, it is typical to have the dispersant at a level a quarter of the way up the well. This allows the sample to be taken into the well cavity by the dispersant. A typical procedure is: 1. Fill the well to 1-2mm below the top of the well. 2. Run an anaerobic fill sequence (press the Anaerobic fill button on the accessory control dialogue). 3. Once complete, use a pipette to remove dispersant so that the well is about a quarter full. Page 4-2 MAN 0389

35 Making a measurement Chapter 4 Sample loss during sample preparation Choose a sample preparation method that ensures that all particles are transferred to the well. A recommended method is to prepare a slurry in a small container and add this to the well using a pipette. Add as a maximum 2ml of sample volume, but 1ml is preferred. Material will usually be seen collecting in the bottom of the container. To take a representative sample of the material: 1. Make the slurry more dilute than is normal for larger volume sample dispersion units. This will ensure that adding slurry does not lead to an excessive concentration. 2. Tilt the container at an angle. 3. Agitate the dispersant by continually filling and discharging the pipette to ensure the material is suspended in the dispersant (rather than sinking to the bottom). 4. Once dispersed, finally fill the pipette with as much of the dispersant as possible and transfer it to the well drop by drop, pausing between drops to allow the sample to fully disperse i.e. monitor the obscuration value until it stabilises. 5. When adding the sample, ensure that it is added directly to the dispersant rather than trickling it down the sides of the well walls. This prevents sample loss through adhesion. Cleanliness Cleanliness is essential; since only 10-50mg of sample is added, it only takes a small amount of cross-contamination from a previous measurement to bias results significantly. Consider the following points when making measurements: When cleaning, rinse the system three or four times. It doesn t use much dispersant, and gives better performance for the next sample. The first rinse of a clean is sometimes best done by injecting 5-10ml bursts of dispersant into the well while the pump is running and the drain valve open. This tends to rinse larger particles through the system. When changing dispersants, blow each dispersant out of the fill tube with a syringe full of air (with the drain open) to reduce cross contamination. When changing over from an oily organic solvent (vegetable oil, etc.) to water, use a biological drain cleaner (containing food enzymes) to clean out the last traces of oil. Hydro 2000µP Page 4-3

36 Chapter 4 Making a measurement Bubbles and pump speeds Control the pump speed to prevent the introduction of bubbles while ensuring that the sample is kept in suspension. This is true for all wet dispersion units but particularly important with the small dispersant volumes of the Hydro 2000µP. The Mastersizer sees bubbles as particles and measures these. Bubbles will vary in size but are typically in the region of 100 microns. In many cases bubbles can be clearly seen as a separate peak when the measurement data is analysed. Consider the following points when making measurements: When filling the system with dispersant, turn off the pump to prevent it introducing bubbles. Fill the system with dispersant slowly to avoid trapping bubbles. When the system is first filled, bring the pump speed up slowly to clear any remaining bubbles, without breaking them into smaller ones. Ideally use the Anaerobic fill sequence (described later) to remove air and bubbles from the system. Take care with the pump speed. The system is designed, and balanced, for water. Other dispersants may tend to well up in the well or pump chamber as the pump speed increases. Full speed (5000 rpm) is too much for most dispersants, so do not use 100% pump by default. See the table in the Anaerobic fill section later for examples of settings. Choose a pump speed high enough to keep the particles in suspension. Using too high a pump speed will tend to draw air into the system. Always fit the well lid during measurements. Finally, on the last wash before filling the system to make a measurement, we recommend that the pump is set to off whilst draining. This is because the action of running the pump whilst draining can cause the formation of small air bubbles in drops of dispersant that may remain in the system after draining. If the system is then filled immediately in order to perform a measurement, these air bubbles are circulated and sized in addition to the required sample. Page 4-4 MAN 0389

37 Making a measurement Chapter 4 Instrument preparation Before starting a measurement, ensure that the correct cell unit is installed in the cell area and then power up the system. The stages are outlined below. Powering up Power up the system by: Switching on the dispersion unit(s). Switching on the optical bench. Switching on the computer and starting the software by double-clicking on the Mastersizer 2000 icon. Filling the cell with clean dispersant Before a measurement fill the cell with clean, degassed dispersant (when the measurement is run the software asks if this has been done). Take care not to let air (either dissolved gasses or bubbles) into the system. The following procedure is recommended to fill the cell unit. Degassing the dispersant Gases dissolved in the dispersant can form bubbles in the cell. To prevent this from happening, we recommend that the dispersant is degassed prior to adding it to the cell unit. The following procedure is suggested if water is used as a dispersant. Warning! This procedure may not be suitable for all dispersants, especially dispersants with low boiling/ignition points. To degas water: 1. Choose a vessel that has a lid and fill the vessel with water. Do not fill the vessel completely at this point. 2. Loosely fit the lid, but do not tighten it. This ensures that pressure does not build up in the vessel, while preventing dust getting in. 3. Place the open vessel in an ultrasonic bath that can be heated. 4. Set the ultrasonic power to 60W and the water bath to 70 C. 5. Degas for 20 minutes. Hydro 2000µP Page 4-5

38 Chapter 4 Making a measurement Vessel Heater Ultrasonic bath ill Once the water has been degassed, a number of bubbles may have formed on the inside surface of the vessel. To remove these, fit the lid to the vessel and very carefully turn the vessel on its side (see the diagram below). Slowly rotate the bottle through one complete revolution - the bubbles will be removed as they meet the air/fluid interface. Bubbles Filling the syringe Take care to avoid air entering the syringe when filling it with dispersant. ill 5639 Warning! Avoid using a syringe with a capacity of more than 20ml. The additional capacity may cause the cell to overflow, causing hazardous conditions within the cell unit. Page 4-6 MAN 0389

39 Making a measurement Chapter 4 To fill the syringe: 1. Insert the syringe into the vessel of dispersant. 2. Draw back the syringe very slowly. Pulling back too quickly will cause boiling on the surface of the syringe plunger (see the diagram below) or air may be dragged back through the syringe seal. Syringe Syringe plunger Boiling Syringe body ill Hold the syringe with the tip pointing upwards, and push the plunger in to displace any air (as shown below). It may be necessary to tap the body of the syringe to displace any air bubbles. ill 5641 i Note Avoid having to refill the syringe half way through filling the cell, as disconnecting and reconnecting the syringe may introduce air into the cell. When filling the standard 20ml syringe, fully draw back the plunger to take up enough dispersant to fill the cell (its approximate capacity is 18ml). Hydro 2000µP Page 4-7

40 Chapter 4 Making a measurement Filling the cell Finally, fill the cell with the clean dispersant. To fill the cell: 1. Connect the syringe to the valve attached to the front of the cell unit. 2. Hold the syringe with the plunger facing upwards (as shown below) so that any bubbles in the syringe rise to the top and are not injected into the cell. Pipe to cell unit Valve 3. Filling the cell now depends on which of the two types of dispersant valve being used: ill 5642 For the non-aqueous valve (suitable for use with a large range of chemically aggressive dispersants) open the tap on the side of the valve. Slowly press the plunger of the syringe (typically over about a 20 second period). Fill the cell until the sample well is almost full (to within 1 or 2mm of the internal well rim. Once full, close the tap on the side of the valve. Note that there is no need to remove the syringe from the valve. The aqueous valve (used with non aggressive dispersants such as water) does not have a tap to control the flow through the valve but acts as a nonreturn valve. To fill the cell, slowly press the plunger of the syringe (typically over about 20 seconds). Fill the cell until the sample well is almost full (to within 1 or 2mm of the internal well rim). i Note For the valve to function correctly as a non-return valve, the syringe must be removed from the valve once the cell is full. Page 4-8 MAN 0389

41 Making a measurement Chapter 4 Anaerobic fill Due to the small volume of the Hydro 2000µP and associated problems of removing bubbles from the system, a special fill sequence called Anaerobic fill can be used. During an anaerobic fill the pump speed is increased in steps to a target speed. A short pause is added between steps to allow bubbles to disperse. To use anaerobic fill click the Anaerobic fill button on the accessory control dialogue s Control tab. The Anaerobic fill dialogue will appear. This contains a field for setting the final pump speed. This is the speed the pump will run at after the fill process has finished. During a manual measurement the last value used will be recalled. During an SOP this will be the pump speed specified in the SOP. For best results set the pump speed field 500rpm above the final speed required. Once the Anaerobic fill sequence is complete the final pump speed can be reset. Example values are given below. Material Pump speed (SOP) Anaerobic fill Glass Beads in: Water Oils Alcohols 2500rpm 3000rpm 2500rpm 3000rpm 3500rpm 3000rpm Latex in water 2000rpm 2500rpm The dialogue prompts the user to fill the well. Once it s full press the Go button. As bubbles escape the level of the dispersant may drop. Once complete, ensure that the well is approximately a quarter full, using a pipette to remove excess dispersant if necessary. Hydro 2000µP Page 4-9

42 Chapter 4 Making a measurement Measuring new samples The above procedures are ideal if the SOP is set up or all the parameters for a manual measurement have been specified. Users measuring a new material must either create or modify an SOP or set up the options for a new manual measurement. This section outlines the setup for measuring a new sample. Measuring new samples - manual measurement The basic procedure is the same as outlined above. When the user selects the Options button in the measurement display, the Measurement Options dialogue appears. This dialogue controls all aspects of the measurement. Use the Materials tab to select a different material and dispersant or define the optical properties of the new material. This tab also allows users to specify options regarding the result calculation. i Note If a material is created or modified the computer calculates a new scattering model. This usually takes between one and 10 minutes, depending on the power of the computer. However, if the ratio of the refractive index of the sample to the dispersant is in the range 0.99 to 1.01, then this time may substantially increase. Under these conditions we recommend that the model is generated overnight. Use the Measurement tab to set up measurement times, set measurement alarms, etc. Press the Document button in the Measurement display to open the Document dialogue. Add relevant details that will allow a user to reproduce the measurement at a later date. All the options available are basically the same when setting up an SOP. For more details of these options see Chapter 4 of the main User Manual. Measuring new samples - SOP measurements Creating an SOP is easy. Select Configure-New SOP; the software will run through an SOP Wizard. This wizard asks a series of questions, such as: what are the optical properties of the sample? what is it suspended in? how fast should the pump be? how much ultrasonic dispersion is required? do any additives need to be added to the sample to aid dispersion? Page 4-10 MAN 0389

43 Making a measurement Chapter 4 how will the result be calculated and displayed? These are all the questions that need to be answered in order to define a measurement. Anyone can create an SOP but typically it is the responsibility of the system administrator. An SOP can be created by a specialist and then distributed to all Mastersizer 2000 users in an organisation. Remember that no instrument needs to be connected to the software to write an SOP. The Malvern software can be installed on a remote computer and SOPs created and edited before they are tried out on an instrument. (The Essentials Manual has details on installing the software on another computer.) A completely new SOP can be created by selecting Configure-New SOP and following the SOP Wizard. An existing SOP can be easily edited either to correct it or to create a new SOP based on it. If several slightly varying SOPs are being saved, it is useful to include the differentiating features in the SOP name e.g. glopalene ultrasound 60, glopalene ultrasound 40. To edit an SOP select Configure-Existing SOP. A tabbed dialogue will appear. Each tab corresponds to a screen from the SOP Wizard. Select a tab and change any of the entries as required. Click OK to save the changes. To create a new SOP based on an existing one, first modify the existing SOP using Configure-Existing SOP. Once all the changes have been made, the Save-As dialogue will appear. Save the SOP under a different name. Hydro 2000µP Page 4-11

44 Chapter 4 Making a measurement Page 4-12 MAN 0389

45 5 Changing cell holder position Introduction The Essentials Manual covers most maintenance procedures. This chapter describes one non-essential procedure, how to move the cell holder from its position on the right of the optical bench, should this be necessary. The Hydro 2000µP is typically configured to be positioned on the right of the optical bench. For users who wish to locate the dispersion unit on the left of the optical bench we recommend that the cell holder be swapped to the other side of the control unit. 1 2 ill 5433 Hydro 2000µP Page 5-1

46 5 Chapter 5 Changing cell holder position To swap over the cell holder: 1. Disconnect all connectors from the control unit. 2. Carefully tip the control unit and the cell holder onto its back to expose the feet and connection plate (as shown on the illustration below). 3. Using a 4mm Allen key, remove the eight screws securing the connection plate. 4. Swap the cell holder to the other side of the control unit. 5. Flip the connection plate over and screw it back into position. 6. Unscrew the four feet and move them to the alternative locations (now located at the outside edge of the assembly) ill 5434 Page 5-2 MAN 0389

47 Part 2 - Appendices

48

49 A Specification Specification Dispersion type Capacity Dispersion mechanisms Modes of operation Weight Cell Control box/cell holder Dimensions Cell Control box/cell holder Particle size range Power requirement Wet. Approx. 20ml AWA Continuously variable and independent pump and ultrasound. AWA Continuously variable pump. Automatic via SOPs. Manual via computer on-screen operating dialogues. 4.25kg (AWA2003), 4kg (AWA2004) 8kg (AWA2003), 7.75kg (AWA2004) Width 108mm Height: 242mm (excluding motor and handle) Height: 335mm (including motor and handle) Depth: 252mm Width: 284mm Height: 338mm Depth: 252mm µm, depending on particle shape and density V / V AC, 48W Only use the PSU and cables provided by Malvern. Using any other PSU may compromise safety and will void any warranty. Hydro 2000µP Page A-1

50 A Appendix A Pump Speed Accuracy Max dispersant viscosity Safety: Ultrasound Frequency Power Safety Specification 0 and rpm rpm, +/-5% of F.S Poise (0.054 Pa.s) Over current and over temperature protected. 48 khz (nominal) 0-20W (dependent upon dispersant) Over current protected. Page A-2 MAN 0389

51 B Chemical compatibility Introduction The Hydro 2000µP is manufactured from materials that give the widest protection from chemical attack. However, it is important to check that any sample or dispersant used is chemically compatible with the materials it will come into contact with in the dispersion unit. This appendix lists all materials that come into contact with the sample and dispersant during normal operation. Component Cell, pump cavity, drain, well, drain tube Internal pipes Impeller, input syringe tube, non-aqueous dispersant inlet valve Drain sump Windows Internal seals Drain and overflow pipes Non-return valve, well lid Beaker Materials 316 stainless steel FEP PTFE Polypropylene Glass Perlast (G70G) Tygon (MH2075) PEEK Pyrex Hydro 2000µP Page B-1

52 B Appendix B Chemical compatibility Page B-2 MAN 0389

53 C Regulatory statements This appendix presents regulatory information. Hydro 2000µP Page C-1

54 C Appendix C CE Declaration of Conformity Regulatory statements The CE badge on this product, shown below, signifies conformance to European Commission Directives. ill 8005 Page C-2 MAN 0389