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Malvern MPT-2 Скачать руководство пользователя страница 55

Vacuum Degasser - Operational guide

Chapter 4

MPT-2 & Degasser

Page 4-3

Principles of operation

The Vacuum degasser consists of a vacuum chamber, degassing tube, variable speed
vacuum pump, microprocessor controller, sensor, and check valves. The titrant
flows into a degassing tube, which is inside a vacuum chamber. Decreased pressure
in the chamber causes the outward movement of gas, dissolved in the titrant, across
the tube wall, thus degassing the titrant; this is in accordance to Henry's Law. The
pressure in the vacuum chamber is established by the vacuum pump and moni-
tored by the microprocessor through an integrated absolute pressure sensor.
Degassed titrant exits the vacuum degasser and enters the pump.

ill 8732

Smart leak detection

An additional benefit of maintaining a constant vacuum level is that a potential leak
in the vacuum degassing system can be observed by monitoring the RPM of the
pump. If a leak occurs within the chamber, the microprocessor will increase the
pump RPM in an attempt to maintain the vacuum level. If the pump cannot main-
tain the vacuum level (if it runs at an elevated RPM for more than 30 minutes), the
yellow LED will flash, indicating a possible leak condition, and the system will shut
down and go into a "safe" mode.

Principles of degassing using Teflon AF®
membranes

This relatively recent addition Teflon AF® membranes to the field of degassing is
due to their having properties not found in other fluoropolymers. The fully amor-
phous nature of this fluoropolymer and its molecular structure creates a molecular
level porosity unlike the mechanically induced porosity in PTFE extruded tubing.
In addition, unlike the process used in extruding PTFE, no extrusion agents are

Channel A

Channel B

Channel C

Block diagram
of a
Vacuum Degasser

MPT-2 Autotitrator

A

B

C

A

Vacuum Degasser

Controller

Vacuum
Pump

Vacuum
Chamber

Pressure
Sensor

Titrants

MAN0318-4.0 - MPT-2 Autotitrator-Degasser.book Page 3 Tuesday, September 4, 2012 12:15 PM

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Содержание MPT-2

Страница 1: ...vern Instruments Limited Enigma Business Park Grovewood Road Malvern Worcs WR14 1XZ U K Tel 44 0 1684 892456 Fax 44 0 1684 892789 www malvern com user manual user manual Zetasizer Zetasizer nano serie...

Страница 2: ......

Страница 3: ...MPT 2 Degasser User Manual MAN0318 Issue 4 0 September 2012...

Страница 4: ...ents Ltd Head office Malvern Instruments Ltd Enigma Business Park Grovewood Road Malvern Worcestershire WR14 1XZ United Kingdom Tel 44 0 1684 892456 Fax 44 0 1684 892789 Zetasizer Malvern and the hill...

Страница 5: ...accessory via an SOP 3 2 Starting a Titration SOP measurement 3 9 The Titration measurement display 3 11 Displaying the Titration measurement results 3 12 Manual control 3 15 Vacuum Degasser Operation...

Страница 6: ...Table of Contents MPT 2 Degasser Page ii MAN 0318 MAN0318 4 0 MPT 2 Autotitrator Degasser book Page ii Tuesday September 4 2012 12 15 PM...

Страница 7: ...Guide before operating the system This manual focuses on specific issues of the Zetasizer nano accessories that are not covered by the above manuals Within the following chapters the manual will detai...

Страница 8: ...This includes a maintenance schedule and associated maintenance procedures for inspecting and cleaning each dispersion unit and its respective components Appendices This chapter appendix details the u...

Страница 9: ...s an internal pump that circulates the sample through the cell in the optical unit A size flow cell will be required if size measurements are to be made The dispenser unit has three titrant containers...

Страница 10: ...Its design assures reliable con tinuous operation and the highest level of continuous performance available with out the need for helium degassing Up to 3 titrant lines may be degassed simultaneously...

Страница 11: ...ion This dialogue is described later in the manual Features of the MPT 2 titrator accessory This section identifies the main features of the MPT 2 titrator accessory ill 8740 Dispersion head The Dispe...

Страница 12: ...ill 8741 Sample container The sample container is the mixing and reaction vessel for the measurement ill 8742 2 4 1 6 5 Magnetic Flea 3 Attaching the sample container MAN0318 4 0 MPT 2 Autotitrator D...

Страница 13: ...ess otherwise stated pH probe The pH probe measures the pH of the sample The performance of the pH probe will deteriorate over time though correct maintenance will extend its life and ensure rapid and...

Страница 14: ...face ten sion 2 Bubbles may be generated from the dropping of titrant into the sample The titrant tubes are the same as those used for the sample If required the titrant tubes can be extended to use a...

Страница 15: ...the syringe drive will descend to first obtain the titrant from the container and then ascend to deliver the titrant to the sample container this is done in conjunction with the manifold assembly and...

Страница 16: ...rs from the top of the titrant containers are colour coded at the manifold to match LED indicators below and the colours in the Titrants SOP dialogue How to fill change and insert the titrant containe...

Страница 17: ...is routed around the tubing connection bracket underneath the dispenser lid The illustration below shows details the various connections How to connect or disconnect the tubing is described in the Cha...

Страница 18: ...The sample to be measured is recirculated through this connector to the cell in the optical unit For biological samples a syringe filter of minimum size 0 22 m can be placed on the exit of this connec...

Страница 19: ...bbles being generated in the sample Rear panel The rear panel contains all electrical connections to the computer and optical unit ill 6828 pH probe connection The pH probe is connected to the pH prob...

Страница 20: ...degassing channels labelled A to C on the front of the degasser Each channel consists of a pair of female connectors which provide the input and output ports for running the titrant lines through the...

Страница 21: ...tes when the vacuum level goes below 100 mm of Hg absolute If an error condition occurs this LED will flash in one of two modes Flashing on and off in even 1 second intervals pump was not able to reac...

Страница 22: ...ort Any gas pumped out of the vacuum chamber exits the unit through the exhaust port Validation Connector Depending on the model there may be a 2 pin receptacle labelled Validation located next to the...

Страница 23: ...zer Nano optical unit Initially the accessory will have been commissioned by a Mal vern Instruments representative Note that when the accessory is to be moved short distances then a sample con tainer...

Страница 24: ...egasser to operate correctly The titrant tubes are fed from the titrant containers through the space at the top of the dispensing area cover towards the degasser input ports and then back again toward...

Страница 25: ...and ensure the tubing lengths will comfortably reach the degasser from the titrator Push a line of tubing through the titrant container clamp above the titrant con tainers until it reaches the base of...

Страница 26: ...ecting the tubing degasser to titrator Caution Never connect the Vacuum Degasser to the output side of the titrator pump The high pressure may cause permanent damage to the degassing membrane Run the...

Страница 27: ...Titrator to the Nano Follow the instructions below for connecting the cell For each cell minimise the tubing within the cell area before inserting into the pinch valve channel Zeta potential measureme...

Страница 28: ...ing by Mal vern Instruments has not shown this to be essential Size measurements The tubing is attached to the sizing flowcell ZEN0023 using threaded inserts As with the folded capillary cell above pu...

Страница 29: ...will only have to be performed at much longer intervals Typically setup before performing a measurement will involve one or more of the following operations Filling the titrant containers Only requir...

Страница 30: ...to 25ml of titrant When the level reaches approximately 5ml it is recommended to re fill the container To refill Remove the titrant container by lifting the container cover up and sliding out the cont...

Страница 31: ...n DO NOT prime the membranes by pushing titrant through the degassing systems This technique can generate several hundred pounds of pressure which might rupture the Teflon AF membrane The maximum reco...

Страница 32: ...ant tube that is to be primed or All to prime all three titrant delivery tubes at once Select the cycles required and press the Prime button to begin the operation Each cycle will pump the volume of t...

Страница 33: ...suitable concentration that gives an inten sity of scattering within recommended values This is checked at the beginning of each titration If the concentration is too high the titration may proceed sl...

Страница 34: ...t the introduction of bub bles into the tubing which will affect the measurement result especially when performing a Zeta measurement If bubbles are present invert the cell while still pumping and tap...

Страница 35: ...er Nano instrument is fully documented in the Zetasizer Nano User Manuals Refer to that manual for details The MPT 2 Multi purpose titrator can be controlled by two methods both via the Zetasizer Nano...

Страница 36: ...dialogue pages will alter slightly to accommodate extra parameters necessary to perform the titration measurement Creating or editing an SOP Measurement Type selection To create a new SOP select File...

Страница 37: ...s dialogue enables the titrants used to be specified and the pump and stirrer speed to be set Titration type pH This is a standard pH titration used to monitor solution prop erties or sample size as a...

Страница 38: ...alongside the titrant containers in the disper sion area Titrant name This is a title for the titrant container Either type the titrant name or select from the scroll down list The name entered here w...

Страница 39: ...pecified the more precise the titration will be The initial start volume will vary according to the titration type being performed generally this will be between 3ml minimum and 25ml maximum When the...

Страница 40: ...volume of the standard sample containers supplied by Malvern is 25ml No risk The display will show green if the predicted vol ume is within the range 5 to 15ml Low risk The display will show amber if...

Страница 41: ...ring The displacement ring will also as act as a weight to keep the container in place when resting on the magnetic stirrer A message will appear to indicate that both the sample and titrant containe...

Страница 42: ...Points Change the Increment value to deter mine how many titration points will be measured The num ber of points to be measured will be shown alongside Increment points is used for defining the number...

Страница 43: ...ructions will appear This may be followed by a Labels dialogue allowing the measurement to be named and any other information about the measurement to be entered Select the OK button when ready The Me...

Страница 44: ...lue has been obtained a measurement will be performed The sample will recirculate if specified 5 With the first measurement complete more titrants will be added to the sample to bring it to the second...

Страница 45: ...ration measurement type pH Zeta example This tab details the titration measurement against the measurement type that is simultaneously produced The graph shown will only appear after the measure ment...

Страница 46: ...cords view all individual associated measurements will be selected too These correspond to the number of titration points measured during the complete titration For example if a Zeta titration measure...

Страница 47: ...name The information shown is generally that which was inputted into the SOP measurement dialogues Cell The Cell section gives details on the Cell type used during the measurement Titrants The Titrant...

Страница 48: ...the top of the graph This is the pH point at which the Zeta potential is zero Please see the Size description in the Zetasizer Nano manual for details on altering the graph Manually controlling the Ti...

Страница 49: ...and prepare the unit prior to a measurement This includes setup instructions such as priming cleaning and cali brating the pH probe The Manual control dialogue is displayed by selecting Tools Instrum...

Страница 50: ...he Clean tab section Refer to the Connection and preparation chapter for instructions on use Prime tab Priming is the process of ensuring that all the titrant delivery tubes are free of air and full o...

Страница 51: ...the Zetasizer Nano software or by selecting the pH calibration icon Brief instructions on performing the cali bration appear on the dialogue Calibration points can be added or removed using the respe...

Страница 52: ...utine this value should constantly change If it does not then the probe is either not immersed sufficiently in the pH solution or the probe is broken or disconnected While a pH calibration is being pe...

Страница 53: ...the start up test the microprocessor ramps the vacuum pump to high RPM to quickly exhaust atmosphere from the vacuum chamber As the vacuum level approaches the preset control value the pump RPM will s...

Страница 54: ...be degassed so long as the instrument is on and running Also refer to Smart leak detection later in this chapter Turning off powering down Turn off the Vacuum degasser when the titrator to which it is...

Страница 55: ...ng the RPM of the pump If a leak occurs within the chamber the microprocessor will increase the pump RPM in an attempt to maintain the vacuum level If the pump cannot main tain the vacuum level if it...

Страница 56: ...the loss of water within the channel The same precautions should be taken to pre vent crystallization within these channels as are taken for the Titrator Refer to the Short term shutdown procedures in...

Страница 57: ...the Dispensing syringes and o ring Changing the filter and tubing A summary of how often these procedures should be carried out is detailed in the maintenance schedule later in this chapter Additiona...

Страница 58: ...titrants being used e g deionised water Ensure that it will reliably clean the sample or titrants used from the tubing Cleaning the sample tubing 1 Remove the sample container and replace with one ful...

Страница 59: ...es of sample being measured In this respect a pH probe can be thought of as a Consumable item Malvern recommends that the probe is replaced every year but this frequency may vary Note three important...

Страница 60: ...be replaced When changing the sample container do not allow the probe to be exposed to air for more than 20 seconds Make sure that the next sample container is ready to attach or alternatively have a...

Страница 61: ...When this happens the pH probe will not respond to pH changes in the sample Carefully brushing this wick can recover performance This effect is reduced by using more dilute samples Calibrating the pH...

Страница 62: ...alibration point press the Add button and enter the calibration pH required Press OK This point will now be added to the calibration point list 4 Repeat the above for all the required calibration poin...

Страница 63: ...buffer point To use a different pH value a new pH buffer point must be added to the selection list Press Add to display the Calibration point dialogue then perform either of the below actions 1 Selec...

Страница 64: ...membrane it will be necessary to soak overnight in 3M KCl solution If these actions are unsuccessful then the electrode will need to be replaced Always ensure that the level of the electrode s electr...

Страница 65: ...it is recommended it should be replaced regularly Replace ment of the filter and any tubing on the titrator is performed using very similar techniques Generally all internal tubing is connected with...

Страница 66: ...ion pH probe calibration Preferably before each titration session pH probe cleaning Once a week or according to in house QC procedures Cleaning the covers Once a month Dispensing syringe and o ring re...

Страница 67: ...er by priming the titrator with dem ineralised water in the titrant container Evaporation leaves salt crystals that may form harmful deposits Remove chloroform or titrants that can decom pose to form...

Страница 68: ...ernal surfaces of the instrument can be done using a clean damp cloth Immediately clean any spills which occur on or near the instrument using methods appropriate for the type of spill Some titrants c...

Страница 69: ...operating correctly when Power and Vacuum green LEDs are illumi nated but pump can t be heard running Due to the design of the pump and degasser the pump is virtually silent at low RPM even though vac...

Страница 70: ...Autotitrator except pump mostly1 16 fittings Inc 4 x manifold red 2 x push on barb connections 4 x manifold green 4 x black tubing grips 4 x manifold cream 1 x Luer filter fittings 4 x plastic nuts 1...

Страница 71: ...z 24Vdc via external power supply Power rating 30VA Recommended maximum fill capacity of standard sample container When filled with titrant When filled with sample 25ml 20ml Modes of operation Automat...

Страница 72: ...er requirement using supplied AC Adapter 100 to 240 VAC 1A 50 to 60 Hz Interchangeable adaptor plugs 4 supplied with AC Adapter Interchangeable to AC Adaptor North America Japan U K Continental Europe...

Страница 73: ...ity 20 to 80 RH without condensation Altitude 0 to 12000 M Connectors Material Size description PEEK 1 4 28 flangeless fittings for 1 16 Outside Diam eter tubing Connecting tubes from MPT 2 Material S...

Страница 74: ...m oil and filtered to remove any contaminants that could affect the sample being measured The flow rate should be adjustable between 2 and 20ml min Vacuum degasser Space Requirements The Vacuum Degass...

Страница 75: ...four interchangeable adaptor plugs are is included to allow the AC adapter to be plugged into the standard electrical wall sockets in North America Japan the U K most countries in continental Europe...

Страница 76: ...rants and Solvents Use only HPLC grade solvents in all analyses Caution The degassing membrane in the Vacuum Degasser is manufactured from Teflon AF Component Materials Sample titrant containers 25ml...

Страница 77: ...m Degasser will result in the dissolution and hence destruction of the membrane Caution Use appropriate care when handling flammable solvents Make sure that there are no leaks in the titrant lines ref...

Страница 78: ...general waste Instead it shall be handed over to the appropriate facility for the recovery and recycling of electrical and electronic equipment By not discarding this product along with other househol...

Страница 79: ...erence received including interference that may cause undesired operation Note This equipment has been tested and found to comply with the limits for a Class A digital device pursuant to part 15 of th...

Страница 80: ...digital apparatus complies with Canadian ICES 003 Cet appareil num rique de la classe A est conforme la norme NMB 003 du Canada VCCI acceptance Japan only The Voluntary Control Council for Interferen...

Страница 81: ...ling the titrator 1 4 Covers 5 10 D Depth A 1 Dilution titration 3 2 3 3 3 6 Dimensions A 1 Dispenser 3 5 Dispenser unit 1 3 Dispensing area cover 1 11 Dispensing syringe 1 9 5 8 Dispersing area 1 9 D...

Страница 82: ...1 Power input 1 13 Power rating A 1 Power supply A 1 Predicted 3 6 Predicted volume 3 6 Preparation before first use 5 4 Preparing the sample 2 11 Prime 3 15 Prime tab 3 16 Priming 2 7 2 9 5 10 Primin...

Страница 83: ...nt concentration 2 9 Titrant containers 1 3 1 10 2 8 Titrant indicators 1 10 Titrant name 3 4 Titrant tubes 1 8 1 11 1 12 Titrants 3 4 Titrants SOP 1 7 Titration Instructions SOP 3 9 Titration Sequenc...

Страница 84: ......

Страница 85: ...alvern Instruments Limited Enigma Business Park Grovewood Road Malvern Worcs WR14 1XZ U K Tel 44 0 1684 892456 Fax 44 0 1684 892789 www malvern com Quick start Self installation guide Zetasizer Malver...

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