Waters 2410 Operator's Manual

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Waters 2410

Differential Refractometer

Operator’s Guide

34 Maple Street

Milford, MA 01757

71500241002, Revision 3

NOTICE

The information in this document is subject to change without notice and should not be construed as a commitment by Waters® Corporation. Waters Corporation assumes no responsibility for any errors that may appear in this document. This guide is believed to be complete and accurate at the time of publication. In no event shall Waters Corporation be liable for incidental or consequential damages in connection with or arising from the use of this guide.

2001 WATERS CORPORATION. PRINTED IN THE UNITED STATES OF AMERICA.



Millennium® PIC and Waters are registered trademarks, and busLAC/E and PowerStation are trademarks of Waters Corporation.

Micromass is a registered trademark and MassLynx is a trademark of Micromass Ltd. All other trademarks or registered trademarks are the sole property of their respective owners.

Note

: When you use the instrument, follow generally accepted procedures for quality

control and methods development. If you observe a change in the retention of a particular compound, in the resolution

between two compounds, or in peak shape, immediately take steps to determine the reason for the changes. Until you determine the cause of a change, do not rely upon the results of the separations.

Note:

The installation category (Overvoltage Category) for this instrument is Level II. The Level II category pertains to equipment that receives its electrical power from a local lev el, such as an electrical wall outlet.

STOP

Attention:

responsible for compliance could void the user’s authority to operate the equipment.

Important:

par l’autorité résponsable de la conformité à la réglementation peut annuler de droit de l’utilisateur à exploiter l’équipement.

Achtung

ausdrückliche Genehmigung der für die ordnungsgemäße Funktionstüchtigkeit verantwortlichen Personen kann zum Entzug der Bedienungsbefugnis des Systems führen.

Avvertenza:

espressamente approvate da un ente responsabile per la conformità annulleranno l’autorità dell’utente ad operare l’apparecchiatura.

Atención

expresamente aprobado por la parte responsable del cumplimiento puede anular la autorización de la que goza el usario para utizar el equipo.

Changes or modiﬁcations to this unit not expressly approved by the party

Toute modeﬁcation sur cette unité n’ayant pas été expressément approuvée

: Jedewede Änderungen oder Modiﬁkationen an dem Gerät ohne die

eventuali modiﬁche o alterazioni apportate a questa unità e non

: cualquier cambio o modiﬁcación realizado a esta unidad que no haya sido

Caution:

Use caution when working with any polymer tubing under pressure:

• Always wear eye protection when near pressurized polymer tubing.

• Extinguish all nearby ﬂames.

• Do not use Tefzel tubing that has been severely stressed or kinked.

• Do not use Tefzel tubing with tetrahydrofuran (THF) or concentrated nitric or sulfuric acids.

• Be aware that methylene chloride and dimethyl sulfoxide cause Tefzel tubing to swell, which greatly reduces the rupture pressure of the tubing.

Attention

pression:

Vorsicht

angebracht:

: soyez très prudent en travaillant avec des tuyaux de polymères sous

• Portez toujours des lunettes de protection quand vous vous trouvez à proximité de tuyaux de polymères.

• Eteignez toutes les ﬂammes se trouvant à proximité.

• N'utilisez pas de tuyau de Tefzel fortement abîmé ou déformé.

• N'utilisez pas de tuyau de Tefzel avec de l'acide sulfurique ou nitrique, ou du tétrahydrofurane (THT).

• Sachez que le chlorure de méthylène et le sulfoxyde de diméthyle peuvent provoquer le gonﬂement des tuyaux de Tefzel, diminuant ainsi fortement leur pression de rupture.

: Bei der Arbeit mit Polymerschläuchen unter Druck ist besondere Vorsicht

• In der Nähe von unter Druck stehenden Polymerschläuchen stets Schutzbrille

tragen.

• Alle offenen Flammen in der Nähe löschen.

• Keine Tefzel-Schläuche verwenden, die stark geknickt oder überbeansprucht sind.

• Tefzel-Schläuche nicht für Tetrahydrofuran (THF) oder konzentrierte Salpeteroder Schwefelsäure verwenden.

• Durch Methylenchlorid und Dimethylsulfoxid können Tefzel-Schläuche quellen; dadurch wird der Berstdruck des Schlauches erheblich reduziert.

Precauzione

pressione:

• Indossare sempre occhiali da lavoro protettivi nei pressi di tubi di polimero pressurizzati.

• Estinguere ogni fonte di ignizione circostante.

• Non utilizzare tubi Tefzel soggetti a sollecitazioni eccessive o incurvati.

• Non utilizzare tubi Tefzel contenenti tetraidrofurano (THF) o acido solforico o nitrico concentrato.

• Tenere presente che il cloruro di metilene e il dimetilsolfossido provocano rigonﬁamento nei tubi Tefzel, che riducono notevolmente il limite di pressione di rottura dei tubi stessi.

: prestare attenzione durante le operazioni con i tubi di polimero sotto

Advertencia:

• Protegerse siempre los ojos a proximidad de tubos de polimero bajo presión.

• Apagar todas las llamas que estén a proximidad.

• No utilizar tubos Tefzel que hayan sufrido tensiones extremas o hayan sido

• doblados.

• No utilizar tubos Tefzel con tetrahidrofurano o ácidos nítrico o sulfúrico concentrados.

• No olvidar que el cloruro de metileno y el óxido de azufre dimetilo inﬂan los tubos Tefzel lo que reduce en gran medida la presión de ruptura de los tubos.

manipular con precaución los tubos de polimero bajo presión:

Caution:

speciﬁed by the manufacturer, the protection provided by the equipment may be impaired.

The user shall be made aware that if the equipment is used in a manner not

Attention:

spéciﬁée par le fabricant, la protection assurée par le matériel risque d’être défectueuses.

Vorsicht:

Verwenddung des Gerätes unter Umständen nicht ordnungsgemäß funktionieren.

Precauzione:

usta in un modo speciﬁcato dal produttore, la protezione fornita dall’apparecchiatura potrà essere invalidata.

Advertencia:

especiﬁcada por el fabricante, las medidas de protección del equipo podrían ser insuﬁcientes.

Caution:

rating.

Attention:

puissance aﬁn d’éviter tout risque d’incendie.

Vorsicht:

gleichen Typs und Nennwertes ersetzen.

Precauzione:

con altri dello stesso tipo e amperaggio.

L’utilisateur doit être informé que si le matériel est utilisé d’une façon non

Der Benutzer wird darauf aufmerksam gemacht, dass bei unsachgemäßer

l’utente deve essere al corrente del fatto che, se l’apparecchiatura viene

El usuario deberá saber que si el equipo se utiliza de forma distinta a la

To protect against ﬁre hazard, replace fuses with those of the same type and

Remplacez toujours les fusibles par d’autres du même type et de la même

Zum Schutz gegen Feuergefahr die Sicherungen nur mit Sicherungen des

per una buona protezione contro i rischi di incendio, sostituire i fusibili

Precaución:

el riesgo de incendio.

sustituya los fusibles por otros del mismo tipo y características para evitar

Caution:

power cord before servicing the instrument.

To avoid possible electrical shock, power off the instrument and disconnect the

Attention:

l’instrument et débranchez le cordon d’alimentation de la prise avant d’effectuer la maintenance de l’instrument.

Vorsicht:

abgeschaltet und vom Netz getrennt werden.

Precauzione:

il cavo di alimentazione prima di svolgere la manutenzione dello strumento.

Precaución:

de alimentación antes de realizar cualquier reparación en el instrumento.

Aﬁn d’éviter toute possibilité de commotion électrique, mettez hors tension

Zur Vermeidung von Stromschlägen sollte das Gerät vor der Wartung

per evitare il rischio di scossa elettrica, spegnere lo strumento e scollegare

para evitar choques eléctricos, apague el instrumento y desenchufe el cab le

Commonly Used Symbols

Direct current Courant continu Gleichstrom Corrente continua Corriente continua

Alternating current Courant alternatif Wechs el s t r om Corrente alternata Corriente alterna

Protective conductor terminal Borne du conducteur de protection Schutzleiteranschluss Terminale di conduttore con protezione Borne del conductor de tierra

Frame or chassis terminal Borne du cadre ou du châssis Rahmen- oder Chassisanschluss Terminale di struttura o telaio Borne de la estructura o del chasis

Caution or refer to manual Attention ou reportez-vous au guide Vorsicht, oder lesen Sie das Handbuch Prestare attenzione o fare riferimento alla guida Actúe con precaución o consulte la guía

Commonly Used Symbols

Caution, hot surface or high temperature Attention, surface chaude ou température élevée Vorsicht, heiße Oberﬂäche oder hohe Temperatur Precauzione, superﬁcie calda o elevata temperatura Precaución, superﬁcie caliente o temperatura elevada

Caution, risk of electric shock (high voltage)•Attention, risque de commotion électrique (haute tension)

Vorsicht, Elektroschockgefahr (Hochspannung) Precauzione, rischio di scossa elettrica (alta tensione) Precaución, peligro de descarga eléctrica (alta tensión)

Caution, risk of needle-stick puncture Attention, risques de perforation de la taille d’une aiguille Vorsicht, Gefahr einer Spritzenpunktierung Precauzione, rischio di puntura con ago Precaución, riesgo de punción con aguja

(Continued)

Caution, ultraviolet light Attention, rayonnement ultrviolet Vorsicht, Ultraviolettes Licht Precauzione, luce ultravioletta Precaución, emisiones de luz ultravioleta

Waters 2410 Differential Refractometer Information

Intended Use

The W aters® 2410 Differential Refractometer can be used for in-vitro diagnostic testing to analyze many compounds, including diagnostic indicators and therapeutically monitoredcompounds. When you develop methods, follow the “Protocol for the Adoption ofAnalytical Methods in the Clinical Chemistry Laboratory,” American Journal ofMedical Technology, 44, 1, pages 30–37 (1978). This protocol covers good operatingprocedures and techniques necessary to validate system and method performance.

Biological Hazard

When you analyze physiological ﬂuids, take all necessary precautions and treat all specimens as potentially infectious. Precautions are outlined in “CDC Guidelines on Specimen Handling,” CDC – NIH Manual, 1984.

Calibration

Follow acceptable methods of calibration with pure standards to calibrate methods. Use a minimum of ﬁve standards to generate a standard curve. The concentration range should cover the entire range of quality-control samples, typical specimens, and atypical specimens.

Quality Control

Routinely run three quality-control samples. Quality-control samples should represent subnormal, normal, and above-normal levels of a compound. Ensure that quality-control sample results are within an acceptable range, and evaluate precision from day to day and run to run. Data collected when quality-control samples are out of range may not be valid. Do not report this data until you ensure that chromatographic system performance is acceptable.

How to Use This Guide Chapter 1

Waters 2410 Theory of Operation

1.1 Overview.........................................................................................................1-1

1.2 Theory of Operation........................................................................................ 1-2

1.2.1 Optical Refraction .............................................................................1-2

1.2.2 Differential Refractometry ................................................................1-7

1.2.3 Common RI Detection Problems ...................................................... 1-9

1.3 Principles of Operation.................................................................................. 1-10

1.3.1 Fluidics............................................................................................. 1-10

1.3.2 Optics .............................................................................................. 1-14

1.3.3 Electronics .......................................................................................1-15

Chapter 2 Installing the 2410 Refractometer

2.1 Introduction.....................................................................................................2-1

2.2 Site Selection and Power Requirements.......................................................... 2-2

2.3 Unpacking and Inspection............................................................................... 2-4

2.4 Making Electrical Power Connections............................................................ 2-5

2.5 Making Fluidic Connections...........................................................................2-5

2.5.1 Connecting a Column or Second Detector.........................................2-6

2.5.2 Connecting to Waste ......................................................................... 2-7

2.5.3 Connecting to a Drip Tray .................................................................2-8

Table of Contents xi

Chapter 3 Making Signal Connections

3.1 Component Connection Overview.................................................................. 3-1

3.2 Making IEEE-488 Signal Connections ........................................................... 3-3

3.2.1 Connecting to a Waters Data System Using the IEEE-488 Bus ........3-3

3.2.2 Connecting to a Waters PowerLine System Controller ..................... 3-7

3.2.3 Connecting to a Manual Injector .......................................................3-7

3.3 Making Non-IEEE-488 Signal Connections................................................... 3-8

3.3.1 Connecting to a Stand-Alone 2690 Separations Module.................3-10

3.3.2 Connecting to the Waters 745/745B/746 Data Module .................. 3-13

3.3.3 Connecting to a Chart Recorder ...................................................... 3-15

3.3.4 Connecting to the Waters 845/860 ExpertEase System ..................3-16

3.3.5 Connecting Injection Trigger Signals .............................................3-16

3.3.6 Polarity Connections .......................................................................3-18

3.4 Connecting the External Column Heaters..................................................... 3-19

Chapter 4 Preparing Solvents

4.1 Common Solvent Problems............................................................................. 4-1

4.2 Selecting a Solvent.......................................................................................... 4-2

4.3 Solvent Degassing........................................................................................... 4-4

4.3.1 Gas Solubility.....................................................................................4-5

4.3.2 Solvent Degassing Methods .............................................................. 4-5

4.3.3 Solvent Degassing Considerations .................................................... 4-6

Chapter 5 Using the 2410 Refractometer

5.1 Using the Front Panel...................................................................................... 5-1

5.1.1 Keypad Functions .............................................................................. 5-4

5.2 Selecting Parameter Values .............................................................................5-9

xii Table of Contents

5.2.1 Sensitivity Guidelines ........................................................................5-9

5.2.2 Scale Factor Guidelines ...................................................................5-10

5.2.3 Time Constant Guidelines ...............................................................5-11

5.2.4 Temperature Guidelines (Ext1 °C, Ext2 °C, Int °C) .......................5-12

5.2.5 Polarity Guidelines ..........................................................................5-13

5.3 Starting Up the 2410 Refractometer..............................................................5-13

5.4 Shutting Down the 2410 Refractometer........................................................5-15

Chapter 6 Maintenance Procedures

6.1 Cleaning the Fluidic Path.................................................................................6-1

6.2 Replacing Fuses...............................................................................................6-3

Chapter 7 Troubleshooting

7.1 Troubleshooting Overvie w ..............................................................................7-1

7.2 Chromatography Troubleshooting...................................................................7-2

7.2.1 Abnormal Baseline.............................................................................7-3

7.2.2 Erratic or Incorrect Retention Times .................................................7-7

7.2.3 Poor Peak Resolution ........................................................................7-9

7.2.4 Incorrect Qualitative/Quantitative Results ......................................7-11

7.3 Diagnostics ....................................................................................................7-13

7.3.1 Operating the Startup Diagnostics....................................................7-13

7.3.2 Operating the User-Initiated Diagnostics ........................................7-13

7.4 Hardware Troubleshooting ............................................................................7-16

Chapter Appendix A Speciﬁcations

Chapter Appendix B Spare Parts/Accessories

Table of Contents xiii

Appendix C Warranty Information

C.1 Limited Express Warranty...............................................................................C-1

C.2 Shipments, Damages, Claims, and Returns.....................................................C-4

Index

xiv Table of Contents

Figures

1-1 Waters 2410 Differential Refractometer..................................................1-1

1-2 Effect of Density on RI............................................................................ 1-4

1-3 Refraction of Light................................................................................... 1-5

1-4 Presence of Sample Changes the Photodiode Signal...............................1-6

1-5 How Refraction Changes

1-6 Waters 2410 Refractometer Fluidics...................................................... 1-11

1-7 Waters 2410 Refractometer Fluidic Paths..............................................1-13

1-8 Waters 2410 Differential Refractometer Optics Bench

Assembly Light Path..............................................................................1-15

2-1 Major Steps in Installing the 2410 Differential Refractometer................2-1

2-2 Dimensions of the 2410 Refractometer ................................................... 2-2

2-3 Waters 2410 Refractometer Rear Panel ...................................................2-4

2-4 Fluidic Connections.................................................................................2-6

2-5 Ferrule and Compression Screw Assembly ............................................. 2-7

.......................................................................1-8

3-1 Waters 2410 Differential Refractometer Rear Panel................................ 3-2

3-2 Overview of Connecting Components to the

2410 Differential Refractometer.............................................................. 3-3

3-3 Waters Millennium System IEEE-488 Connections................................ 3-4

3-4 Waters 845/860 System IEEE-488 Connections......................................3-4

3-5 Waters Alliance System IEEE-488 Connections .....................................3-5

3-6 Waters PowerLine System Controller IEEE-488 Connections................ 3-7

3-7 Waters 2410 Rear Panel Analog-Out/Event-In Connectors.....................3-9

3-8 Auto Zero Connections Between the 2690 Separations Module

and the 2410 Refractometer................................................................... 3-11

3-9 Chart Mark Connections Between the 2690 Separations Module

and the 2410 Refractometer................................................................... 3-12

3-10 Chart Mark and Auto Zero Connections Between

the 2690 Separations Module and the 2410 Refractometer................... 3-13

Table of Contents xv

3-11 Connections to a Waters 745/745B/746 Data Module........................... 3-14

3-12 Analog Output Connections to a Chart Recorder .................................. 3-15

3-13 Analog Output Connections to the Bus SAT/IN Module....................... 3-16

3-14 Auto Zero Connectionto a Manual Injector...........................................3-17

3-15 Chart Mark Connections to a Manual Injector ...................................... 3-18

3-16 2410 Refractometer External Column Heater Ports ..............................3-20

5-1 Display, LED Indicators, and Keypad......................................................5-2

5-2 Effects of Sensitivity Settings................................................................5-10

5-3 Effects of Filter Time Constant Settings................................................5-12

6-1 Removing and Replacing Fuses...............................................................6-4

xvi Table of Contents

Tables

1-1 Fluidic Line Inner Diameters............................................................ 1-12

2-1 Installation Site Requirements.................................................................2-3

3-1 Component Connection Summary...........................................................3-1

3-2 Waters 2410 Refractometer Inject Start Connections........................ 3-6

3-3 Waters 2410 Connections to a Manual Injector ................................ 3-7

3-4 Waters 2410 Analog-Out/Event-In Connections............................... 3-9

3-5 Auto Zero Connections Between the 2690 Separations Module

3-6 Chart Mark Connections Between the 2690 Separations Module

3-7 Chart Mark and Auto Zero Connections Between the

3-8 Analog Output Connections to a 745/745B/746 Data Module ........ 3-13

3-9 Analog Output Connections to a Chart Recorder............................ 3-15

and the 2410 Refractometer ........................................................... 3-10

and the 2410 Refractometer ........................................................... 3-11

2690 Separations Module and the 2410 Refractometer................... 3-12

3-10 Analog Output Connections to the Bus SAT/IN Module................. 3-16

3-11 Auto Zero Connections to a Manual Injector.................................. 3-17

3-12 Chart Mark Connections to a Manual Injector ................................ 3-18

3-13 Polarity Options............................................................................. 3-19

4-1 Refractive Indices of Common Solvents..................................................4-3

5-1 Indicator LED Functions..........................................................................5-3

5-2 Keypad Functions............................................................................ 5-4

6-1 Voltage and Fuse Requirements...............................................................6-4

7-1 Abnormal Baseline Troubleshooting................................................ 7-4

7-2 Retention Time Troubleshooting...................................................... 7-7

Table of Contents xvii

7-3 Resolution Troubleshooting ........................................................... 7-10

7-4 Incorrect Results Troubleshooting.................................................. 7-12

7-5 User Diagnostics............................................................................ 7-14

7-6 Waters 2410 Hardware Troubleshooting ......................................... 7-16

A-1 Operational Speciﬁcations...................................................................... A-1

A-2 Integrator Output..............................................................................A-2

A-3 Optical Component Speciﬁcations....................................................A-2

A-4 Environmental Speciﬁcations...........................................................A-2

A-5 Dimensions ......................................................................................A-3

A-6 Electrical Speciﬁcations...................................................................A-3

A-7 Power Source Speciﬁcation..............................................................A-3

B-1 Recommended Spare Parts ...............................................................B-1

C-1 Waters 2410 Warranty Periods.................................................................C-4

xviii Table of Contents

How to Use This Guide

Purpose of This Guide

The

Waters 2410 Differential Refractometer Operator’ s Guide

Waters® 2410 Differential Refractometer and provides installation and maintenance procedures.

Audience

This guide is intended for use by anyone interested in installing, using, maintaining, and troubleshooting the 2410 differential refractometer.

Structure of This Guide

The

Waters 2410 Differential Refractometer Operator’s Guide

appendixes. Each page is marked with a tab and a footer to facilitate access to information within the chapter or appendix.

The table below describes the material covered in each chapter and appendix.

describes the features and use of the

is divided into chapters and

Chapter 1, Waters 2410 Theory of Operation

Chapter 2, Installing the 2410 Refractometer

Chapter 3, Making Signal Connections

Chapter 4, Preparing Solvents

Chapter 5, Using the 2410 Refractometer

Chapter 6, Maintenance Procedures

Chapter 7, Troubleshooting

Describes the product and the principles of differential refractometry and 2410 differential refractometer operation.

Describes the 2410 differential refractometer installation procedures.

Describes how to connect other components of your chromatography system to the 2410 differential refractometer.

Discusses the importance of ﬁltering and degassing solvents for effective operation.

Describes how to power on and off and operate the 2410 differential refractometer.

Describes maintenance and parts replacement procedures for the 2410 differential refractometer.

Provides tables describing symptoms, possible causes, and corrective actions for 2410 differential refractometer operational problems.

xix

Appendix A, Speciﬁcations

Provides speciﬁcations for the 2410 differential refractometer.

Appendix B, Spare Parts/Accessories

Appendix C, Warranty Information

Lists the recommended spare parts for the 2410 differential refractometer.

Includes warranty and service information for the 2410 differential refractometer.

Waters 2410 Theory of Operation

1.1 Overview ........................................................... 1-1

1.2 Theory of Operation.......................................... 1-2

1.3 Principles of Operation.................................... 1-10

Waters 2410 Theory of Operation

This chapter introduces you to the Waters® 2410 Differential Refractometer. It summarizes the 2410 differential refractometer features and the principles of differential refractometry, and describes the theory and principles of operation.

Refer to Appendix A, Speciﬁcations, for system speciﬁcations, and to

Solvents

1.1 Overview

The Waters 2410 Differential Refractometer, shown in Figure 1-1, is a differential refractive index detector designed for high performance liquid chromatography applications. It can operate as a stand-alone unit with an integrator or chart recorder, or with a Waters system controller or Waters data system.

, for solvent considerations.

Chapter 4, Preparing

Waters 2410

Differential Refractometer Detector

TP01531

Figure 1-1 Waters 2410 Differential Refractometer

Overview 1-1

Range and Sensitivity

The 2410 detector functions with solvents with refractive indices between 1.00 and 1.75. The measurement range of the instrument is 5 × 10–8 to 5 × 10–3 refractive index units full scale (RIUFS).

Features

Features of the 2410 differential refractometer include:

• Patented countercurrent heat exchanger and temperature-controlled cell for stable operation under varying conditions

• Auto zero and auto purge for automated operation

• Built-in pressure relief to protect ﬂow cell

• Auto diagnostics

• Two external column heater controls

• Battery backup to retain parameter settings when the detector is powered off or during power interruptions

• Long-life LED light source

1.2 Theory of Operation

The W aters 2410 Dif ferential Refractometer uses optical refraction to monitor the concentrations of sample components in your eluent. This section describes:

• Optical refraction

• Differential refractometry

• Common problems in refractometry

1.2.1 Optical Refraction

When a beam of light passes from one medium into another, it changes its speed. If the light enters the second medium at an angle that is not perpendicular to the medium’s surface, the light is bent (refracted).

The extent to which a medium refracts light is its velocity of light in a vacuum to the velocity of light in the medium. It is a physical property of the medium, with a dimensionless integer value represented by the letter n.

This section discusses:

• Factors that affect RI

1-2 Waters 2410 Theory of Operation

refractive inde x

(RI), calculated as the ratio of the

• Measuring refraction

• Using changes in RI for sample detection

Factors That Affect RI

The refractive index of a medium is solely dependent on the speed of light in the medium. The speed of light in a medium is constant for a given wa velength of light at a speciﬁed temperature and pressure.

Wavelength

The refractive index of a medium has a speciﬁc value that changes with the wavelength of the incident light beam. Since the 2410 differential refractometer uses monochromatic light at a ﬁxed wavelength, the effect of different wavelengths of light on RI is not discussed in this guide.

Density

The density of the medium also affects its RI. At a ﬁxed wavelength, the relationship between the density of a medium and its RI is generally, but not necessarily, linear. The most important of the factors that affect the density of a medium are:

• Composition

• Temperature

• Pressure

Figure 1-2 illustrates the effect of density on the RI of two solutions. The refractive index of a sucrose solution changes linearly with concentration over this range of compositions, but a methanol solution exhibits a nonlinear region between concentrations of 45 and 55 percent.

Theory of Operation 1-3

Weight Percent Sucrose in Water

Refractive Index

Density (g/mL)

Weight Percent Methanol in Water

Refractive Index

Figure 1-2 Effect of Density on RI

1-4 Waters 2410 Theory of Operation

Density (g/mL)

Measuring Refraction

The extent to which a beam of light is refracted when it enters a medium depends on two factors:

• The angle at which the light enters the new medium (the

• The refractive indices of the new media

angle of incidence

)

The angle of a refracted light beam through the new medium is its

angle of refraction

Figure 1-3 illustrates the relationship between angle of incidence, angle of refraction, and refractive index.

Incoming Light Beam Perpendicular to Surface

Angle of Incidence

Medium 1, RI = n Medium 2, RI = n

Refracted Light Beam

1 2

Angle of Refraction

Figure 1-3 Refraction of Light

The relationship between the refractive indices of the two media and the angles of incidence and refraction is described by Snell’s Law:

n1(sin

where:

= Angle of incidence

= Angle of refraction

= RI of medium 1

= RI of medium 2

) = n2(sin

)

Theory of Operation 1-5

You can use Snell’s Law to calculate the RI of a sample solution from the angle of incidence, the RI of the solvent, and the angle of refraction.

Using Changes in RI for Sample Detection

As the separated components of a sample pass through the refractometer ﬂow cell:

• The composition of the sample solution in the ﬂow cell changes.

• The RI of the solution changes.

• The light beam passing through the solution is refracted.

The refractometer detects the position of the refracted light beam, creating a signal that differs from the baseline signal.

Figure 1-4 shows how refraction by the sample in the ﬂow cell changes the proportion of light on each element of the photodiode.

Dual Element

Dual-Element

Photodiode

Collimating

Collimating Lens

Lens

Sample Side

Sample Side of Flow Cell

of Flow Cell

Sample in

Sample Side

of Flow Cell

Reference

Reference Side of Flow Cell

Side of

Flow Cell

Figure 1-4 Presence of Sample Changes the Photodiode Signal

1-6 Waters 2410 Theory of Operation

Incident Light

Reference Side

of Flow Cell

Reference Side of Flow Cell

By keeping wavelength, temperature, and pressure constant, the changes in RI measured by the refractometer are due only to changing sample concentration. A solution with a high concentration of a solute refracts a beam of light more than a dilute solution. Therefore, high concentrations of sample yield large peaks.

1.2.2 Differential Refractometry

The 2410 differential refractometer can measure extremely small changes in refractive index to detect the presence of sample. The small difference in RI between a reference solution and a sample solution is referred to as ∆n. ∆n is expressed in refractive index units (RIU).

The 2410 differential refractometer measures ∆n values as small as 5 × 10–8 RIU by detecting the difference in the amount of light falling upon each of the elements of the dual-element photodiode (see Figure 1-4).

External Angle of Deﬂection

The amount of light falling upon the elements of the photodiode is determined by the external angle of deﬂection (φ), as shown in Figure 1-5. The φ determines the magnitude of the shift (∆x) of

the image cast on the photodiode by the light beam. Figure 1-5 illustrates the external angle of deﬂection (φ) and its dependence on the difference in RIs

between the reference and sample sides of the ﬂow cell.

Theory of Operation 1-7

Reference Side

of Flow Cell

n + ∆n

Sample Side

of Flow Cell

= ∆x

Figure 1-5 How Refraction Changes

Effect of Refraction on

As the beam of light moves along the light path to the photodiode, it encounters and is refracted by the air in the optics bench assembly, the fused quartz walls of the ﬂow cell, the solvent in the reference side of the ﬂow cell, and the solution in the sample side of the ﬂow cell.

Of these refractors, only the solution in the sample side of the ﬂow cell changes over the course of a run. As a result, the reference external angle of deﬂection (φ) does not change until a change in the RI of the sample causes the light beam to be refracted from its zero position.

1-8 Waters 2410 Theory of Operation

The relationship between the external angle of deﬂection (φ) and the RI of the sample solution is expressed as:

∆n ≅ φ/tan

where: ∆n =Difference in RI between the solvent and the solvent-sample solution

=External angle of deﬂection (in radians)

=Angle of incidence (in radians)

Effect of Refraction on the Photodiode Signal

The change in φ determines the shift (∆x) of the light beam on the photodiode. Because the 2410 differential refractometer uses a dual-pass optics bench assembly , the light beam passes through the ﬂow cell twice before reaching the photodiode, doubling the image shift.

The relationship between the image shift (∆x) at the 2410 detector photodiode and the change in RI of the solution is expressed as:

∆x = 2Y(tanθ) ∆n

where: ∆x = Distance of the image shift at the photodiode

Y = Distance from the ﬂow cell to the photodiode

=Angle of incidence

∆n =Difference in RI between solvent and sample solution

The angle of incidence (θ) and the distance to the photodiode (Y) are ﬁxed in the refractometer, so the equation becomes:

∆x = C ∆n

Where: C = A constant representing the ﬁxed values By detecting how far the image shifts (∆x), the refractometer measures the difference in RI (∆n)

between the solvent-sample solution and the solvent alone. The shift in the amount of the light beam striking each element of the dual-element photodiode

results in a change in the output voltage from the 2410 detector. The integrator or chart recorder registers the changes in output voltage as peaks in your chromatogram.

1.2.3 Common RI Detection Problems

Changes in solution density caused by factors other than sample concentration are the most common source of problems in RI detection. Changes in solution density can be due to:

• Environmental factors such as changes in temperature or pressure

• Inhomogeneities in the solution

Theory of Operation 1-9

Environmental Factors

Even small changes in ambient temperature can cause baseline drift. Backpressure pulses from a dripping waste tube can cause short-term baseline cycling. Refer to Chapter 7, T roubleshooting, for more information.

Inhomogeneities in Solution

The differential refractometer measures the difference in refraction between a pure reference solvent and a homogeneous sample solution within a chromatographic band. If the sample solution is not homogeneous, the light passing through the sample may be absorbed, scattered, or refracted unpredictably. This can result in shifts in retention time and broad, tailing peaks. Most common inhomogeneity problems are due to improper solvent preparation. See Chapter 4, Preparing Solvents, for more information.

1.3 Principles of Operation

This section describes the design of the 2410 refractometer and its principles of operation, including:

• Fluidics

• Optics

• Electronics

1.3.1 Fluidics

The ﬂuidic path of the 2410 refractometer includes the following components, some of which are shown in Figure 1-6:

• Countercurrent heat exchanger

• Flow cell, with sample and reference sides

• Solenoid valve

• Pressure relief valve

• Inlet and outlet tubing

1-10 Waters 2410 Theory of Operation

Pressure Relief

Valve

Solenoid

Valve

Outlet T ubing

(Blue)

Inlet Tubing (Red)

TP01532

Figure 1-6 Waters 2410 Refractometer Fluidics

Countercurrent Heat Exchanger

The 2410 refractometer uses a patented countercurrent heat exchanger to minimize temperature ﬂuctuations in the sample stream. In the countercurrent heat exchanger, the sample and reference inlet and outlet lines run adjacent to each other. All four lines are copper-coated to facilitate heat exchange.

Flow Cell

The ﬂow cell consists of two fused quartz hollow prisms. Each has an inlet and outlet. One of the prisms is the sample side of the ﬂow cell through which a constant ﬂow of eluent passes during analysis.

The other prism is the reference side of the ﬂow cell. It is ﬁlled with clean solvent when you purge the 2410 refractometer during equilibration. When you switch from purge to normal operation, the solenoid valve opens and the pressure relief valve shuts, stopping the flow of solvent through the reference prism but leaving the cell ﬁlled with solvent.

Principles of Operation 1-11

Solenoid V alve

During normal operation, the solenoid valve remains open. Fluid that passes through the sample side of the ﬂow cell ﬂows through the solenoid v alv e and out through the outlet tubing (blue) to the waste reservoir.

When you purge the 2410 refractometer, the solenoid valve closes, causing ﬂuid passing through the sample side of the ﬂow cell to ﬂow out through the reference side of the ﬂow cell, through the purge outlet tubing (blue).

Pressure Relief Valve

During normal operation, the pressure relief valve is closed, opening only if the pressure gets too high. This protects the ﬂow cell, which has a maximum pressure rating of 100 psi.

During purging, ﬂuid moving through the sample and reference sides of the ﬂow cell goes out through the pressure relief valve to the waste reserv oir . Figure 1-7 indicates the paths of solvent and sample in the 2410 refractometer during normal operation and during a purge. Table 1-1 provides the inner diameters of the sample and reference ﬂuidic lines.

Table 1-1 luidic Line Inner Diameters

Fluidic Line

Sample In 0.009

Sample Out 0.040

Reference In 0.020

Reference Out 0.040

Inner Diameter

(inches)

1-12 Waters 2410 Theory of Operation

Pressure

Relief Valve

Flow Cell

Reference

Side

T Block

Sample

Side

Solenoid

Heat ExchangerHeat Exchanger

Valve

= normal ﬂow path

= purge flow path

Purge Out Out Port In Port

Figure 1-7 Waters 2410 Refractometer Fluidic Paths

from Columnto Waste to Waste

(red) (blue)(blue)

Fluidic Path During Analysis

During analysis, the solvent-sample:

1. Flows in through the inlet tubing port.

2. Passes through the Sample In tube of the countercurrent heat exchanger.

3. Flows through the sample side of the ﬂow cell.

4. Flows out though the Sample Out tube of the countercurrent heat exchanger.

5. Passes through the solenoid valve to the outlet tubing port.

Fluidic Path During Purge

When you purge the 2410 refractometer ﬂuidic path, solvent:

1. Flows in through inlet tubing port.

2. Passes through the Sample In tube of the countercurrent heat exchanger.

Principles of Operation 1-13

3. Flows through the sample side of the ﬂow cell.

4. Flows out through the Sample Out tube of the countercurrent heat exchanger to the closed solenoid valve.

5. Passes through the Reference In tube of the countercurrent heat exchanger.

6. Flows through the reference side of the ﬂow cell.

7. Flows out through the Reference Out tube of the countercurrent heat exchanger.

8. Flows out through the pressure relief valve to the purge outlet tubing port.

1.3.2 Optics

The 2410 refractometer optics bench assembly (Figure 1-8) consists of the following components:

• LED source lamp

• LED lens mask

• LED lens

• Flow cell, with sample and reference sides

• Mirror

• Collimating lens

• Dual-element photodiode

Figure 1-8 shows the path of the light beam as it passes through the components in the optics bench assembly.

As shown in Figure 1-8:

1. Light from the LED is focused by the focusing lens through the aperture and collimating lens to form a beam.

2. The light beam passes through the sample and reference sides of the ﬂow cell to the mirror.

3. The light beam is reﬂected back through both sides of the ﬂow cell and the collimating lens to the dual-element photodiode.

The difference in the amount of light striking the elements of the photodiode (because of sample refraction) results in a deﬂection from the baseline on the chromatogram.

1-14 Waters 2410 Theory of Operation

Collimating Lens

LED Lens

Figure 1-8 Waters 2410 Differential Refractometer Optics Bench Assembly Light Path

Dual-Element

Photodiode

LED

Lens

Mask

Flow Cell

MirrorHeat Exchanger CoilsLED

1.3.3 Electronics

TP01536

The 2410 refractometer has both analog and digital components, and includes hardware such as the front panel keyboard and printed circuit (PC) boards and their interconnections. The following PC boards are included in the 2410 refractometer electronics.

• CPU Board – Provides the interface between the analog input signals from the optics and

the microprocessor, for further signal conditioning. Generates analog output signals, drives the LED, Auto Zero, and signal compensation electronics, and stores and executes input from the front panel keypad and the rear panel contact closures. Provides communication between the 2410 refractometer and external devices through the IEEE-488 interface and terminal strip input/output connections.

• Front Panel Board – Controls the keypad, indicators, and display.

• Power Distribution Board – Distributes DC voltages to the CPU board, fan, and heaters.

Provides the electronic switching for control of the oven compartment.

Principles of Operation 1-15

1-16 Waters 2410 Theory of Operation

Chapter 2

Installing the 2410 Refractometer

2.1 Introduction....................................................... 2-1

2.2 Site Selection and Power Requirements............ 2-2

2.3 Unpacking and Inspection................................. 2-4

2.4 Making Electrical Power Connections .............. 2-5

2.5 Making Fluidic Connections............................. 2-5

Installing the 2410 Refractometer

This chapter describes the procedures for selecting the site for installing the Waters 2410 Differential Refractometer, unpacking and inspecting the instrument, installing fuses, and making ﬂuidic connections. For information on connecting the 2410 refractometer to other devices, see Chapter 3.

2.1 Introduction

Figure 2-1 shows the major steps in installing the Waters 2410 Differential Refractometer.

Start installation

procedure.

Select appropriate

site.

Unpack and

inspect.

Install 2410

refractometer.

Figure 2-1 Major Steps in Installing the 2410 Differential Refractometer

Make power

connections.

Make ﬂuidic

connections.

Make signal

connections to

other devices.

Installation

complete.

Introduction 2-1

Figure 2-2 shows the dimensions of the 2410 refractometer.

STOP

Waters 2410

Differential Refractometer Detector

19.8 inches (50.3 cm)

11.2 inches (28.4 cm)

Figure 2-2 Dimensions of the 2410 Refractometer

Attention: Access to the instrument inside the top cover is not required. All required access is through the left front panel where the ﬂuidic connections are located (see Section 2.5, Making Fluidic Connections).

8.2 inches (20.8 cm)

TP01530

2.2 Site Selection and Power Requirements

Reliable operation of your 2410 refractometer depends on a proper installation site and a suitable power supply.

Site Selection Requirements

Install the Waters 2410 Differential Refractometer in an area that meets the requirements listed in Table 2-1.

2-2 Installing the 2410 Refractometer

Table 2-1 Installation Site Requirements

Parameter Requirement

Operating temperature range +15 °C to +32.2 °C (59 °F to 90 °F); avoid direct

exposure to sunlight and heating/cooling vents.

Storage temperature range –40 °C to 70 °C (–104 °F to 158 °F)

Relative humidity 20% to 80%, noncondensing

Storage humidity range 0% to 90%, noncondensing Bench space At least 11.2 in. (28.4 cm) wide × 24.8 in. (63 cm)

deep × 8.2 in. (20.8 cm) high (includes 5 in. [12.7 cm] clearance at rear)

Static electricity < 8 kV contact

Power Grounded ac, 100/240 Vac, 50/60 Hz

Surface orientation Level (ensures proper drip tray function)

Power Requirements

The 2410 refractometer, which operates over the range 100 Vac to 240 Vac, is shipped from the factory with two 2.0 A fuses.

Caution: To avoid electrical shock, power off the 2410 refractometer and unplug the power cord from the rear panel receptacle before you replace a fuse.

Caution: T o reduce the risk of ﬁre hazard, alwa ys replace the fuse with the same type and rating.

The two fuses are located above the power input receptacle within the power input module on the rear panel (Figure 2-3).

Site Selection and Power Requirements 2-3

Inputs

and Outputs

Ext. 2 Ext. 1

Fuse Holder

Figure 2-3 Waters 2410 Refractometer Rear Panel

To replace a fuse in the 2410 refractometer, see Section 6.2, Replacing Fuses.

2.3 Unpacking and Inspection

The Waters 2410 refractometer shipping carton contains:

• Certiﬁcate of Structural Validation

• Waters 2410 Differential Refractometer

• Startup Kit

• Waters 2410 Differential Refractometer Operator’s Guide

• Release Notes

IEEE-488

Interface

Connection

Power Input Receptacle

TP01531

To unpack the 2410 refractometer:

1. Check the contents of the shipping carton against the packing list to ensure you have received all items.

2. Save the shipping carton for future transport or shipment.

2-4 Installing the 2410 Refractometer

If you see any damage or discrepancy when you inspect the contents of the carton, immediately contact the shipping agent. U.S. and Canadian customers only , also contact W aters T echnical Service at (800) 252-4752. Other customers, call your local W aters subsidiary or your local W aters T echnical Service Representative, or call Waters corporate headquarters for assistance at (508) 478-2000 (U.S.).

Note: Make sure the instrument serial number on the rear panel nameplate or inside the left front panel corresponds to the number on the instrument validation certiﬁcate.

For more information about shipments, damages, and claims, see Appendix C, Warranty Information.

2.4 Making Electrical Power Connections

To connect the 2410 refractometer to the ac power supply:

1. Plug the receptacle end of the power cord into the ac power input receptacle on the rear panel of the detector (Figure 2-3).

2. Plug the other end of the power cord into a properly grounded ac power source.

For information about the remaining rear panel electrical connections, see Chapter 3, Making Signal Connections.

2.5 Making Fluidic Connections

Caution: To avoid chemical hazards, always observe good laboratory practices when handling solvents. Refer to the Material Safety Data Sheets for solvents in use.

This section describes the procedures for connecting the 2410 refractometer to:

• A column or another detector

• A waste container

• The drip tray

The ﬂuidic connections for the 2410 refractometer are located to the left of the keypad on the front panel (Figure 2-4).

Making Electrical Power Connections 2-5

Pressure Relief

Valve

Solenoid Valv e

Outlet Tubing

(blue)

Drip Tray Fitting

(under oven)

Inlet Tubing (red)

Figure 2-4 Fluidic Connections

2.5.1 Connecting a Column or Second Detector

Note: If you are using more than one detector in your system, the W aters 2410 Diff erential Refractometer must be connected as the last detector in line.

Required Materials

• 1/16-inch stainless steel tubing, 0.009-inch ID (from Startup kit)

• Waters 1/16-inch stainless steel tubing cutter or ﬁle

• Pliers, cloth-covered

• Two compression ﬁttings and ferrules (from Startup kit)

• 5/16-inch open-end wrench

TP01532

To connect a column or other detector to the 2410 refractometer:

1. Measure the minimum length of tubing needed to connect the column or other detector outlet to the inlet tubing port.

2-6 Installing the 2410 Refractometer

2. Cut the tubing to the required length.

a. Use the stainless steel tubing cutter or a ﬁle with a cutting edge to scribe the

circumference of the tubing at the desired end point.

b. Grasp the tubing on both sides of the scribed mark with cloth-covered pliers (to prevent

marring the surface) and gently work the tubing back and forth until it separates.

c. File the ends smooth and straight for maximum column efﬁciency, and remove all

burrs.

3. Slide a compression screw and ferrule over one end of the tubing, as shown in Figure 2-5.

Compression

Screw

Tube

Distance (determined by

TP01139

Figure 2-5 Ferrule and Compression Screw Assembly

4. Bottom the tubing in the inlet tubing port ﬁtting of the refractometer, then seat the ferrule by tightening the compression screw 3/4-turn past ﬁnger-tight with the 5/16-inch open-end wrench.

5. Repeat steps 3 and 4 to connect the tubing to the outlet ﬁtting of the column or another detector.

each application, such as union or column ﬁtting)

2.5.2 Connecting to Waste

Because the 2410 refractometer ﬂow cell is very sensitive to backpressure, be sure to use waste tubing that is 0.040-inch ID and that is no more than 18 to 24 inches (45 to 60 cm) long.

Ferrule

Tubing End (straight and smooth to achieve maximum column efﬁciency)

Required Materials

• 1/16-inch stainless steel tubing, 0.040-inch ID (from Startup kit)

• Waters 1/16-inch stainless steel tubing cutter or ﬁle

• One compression ﬁtting and ferrule (from Startup kit)

Making Fluidic Connections 2-7

• 5/16-inch open-end wrench

• Waste container

To connect the 2410 refractometer to waste:

1. Cut the minimum length of tubing needed, as described in Section 2.5.1, Connecting a Column or Second Detector.

2. Slide the compression ﬁtting and ferrule over one end of the 0.040-inch tubing, as shown in Figure 2-5.

3. Bottom the tubing in the outlet tubing port ﬁtting of the refractometer, then seat the ferrule by tightening the compression screw 3/4-turn past ﬁnger-tight with the 5/16-inch open-end wrench.

4. Place the waste container lower than, or at the same level as, the 2410 refractometer.

5. Place the free end of the tubing in the waste container.

STOP

Attention: The maximum pressure for the 2410 refractometer ﬂow cell is 100 psi. The

ﬂow cell could be damaged if this pressure is exceeded.

2.5.3 Connecting to a Drip Tray

The 2410 refractometer contains a drip tray underneath the ﬂow cell behind the front panel to direct solvent leaks to the front of the unit.

Connecting the drip tray is usually unnecessary, but, if you connect it, be sure to position the waste container below the drip tray outlet.

Required Materials

• PTFE tubing, 0.063-inch ID (from the Startup kit)

• Razor blade

To connect the drip tray:

1. Cut a length of PTFE tubing sufﬁcient to reach between the drip tray and the waste container.

2. Connect the tubing to the white plastic ﬁtting located under the oven of the 2410 refractometer (see Figure 2-4).

3. Insert the other end of the tubing into the waste container.

2-8 Installing the 2410 Refractometer

Chapter 3

Making Signal Connections

3.1 Component Connection Overview .................... 3-1

3.2 Making IEEE-488 Signal Connections ............. 3-3

3.3 Making Non-IEEE-488 Signal Connections..... 3-8

3.4 Connecting the External Column Heaters....... 3-19

Making Signal Connections

This chapter describes procedures for making signal connections between the Waters 2410 Differential Refractometer and other HPLC system components.

3.1 Component Connection Overview

Table 3-1 summarizes the signal connections needed to connect the 2410 refractometer to other HPLC system components.

Table 3-1 Component Connection Summary

Connector Type Component

IEEE-488 Connections

IEEE-488 Connector • Millennium Chromatography Manager

through the busLAC/E card

• Waters 845/860 Data System through the LAC/E or busSAT/IN Module

• Waters PowerLine™ System Controller

• Waters 2690 Separations Module

Non-IEEE-488 Connections

Analog outputs • 745/745B/746 Data Module (integrator

or data system using the A/D interface)

• Chart recorder

• Compressed data output

Event inputs • System controller (used with the Waters

2690 Separations Module and the 600 Series solvent delivery system)

• Waters 700 series or a non-Waters autosampler

• Waters or non-Waters manual injector

9-Pin DIN • Waters or non-Waters manual injector

• Two optional external column heaters

Component Connection Overview 3-1

Figure 3-1 shows the rear panel locations of the connectors used to operate the 2410 refractometer with external devices.

Analog-Out

and Event-In

Connectors

9-Pin DIN

Connectors (for

External Column

Heaters)

Fuse Holder

IEEE-488 Interface

Power Input

Figure 3-1 Waters 2410 Differential Refractometer Rear Panel

The signal connections you need to make to your 2410 refractometer depend on the signal connections available on the other instruments in your HPLC system.

Figure 3-2 provides an overview of the steps to follow to connect the 2410 refractometer to other instruments in your HPLC system.

TP01531

3-2 Making Signal Connections

Start Signal

Connection Procedure

Connect to

IEEE-488

Bus?

Connect

to Non-IEEE

Instrument, Such as Integrator,

Chart Recorder,

bus SAT/IN,

etc.

Signal Connections

Complete

Yes

Install IEEE-488

Cable

Install Event and I/O

Cable(s)

Figure 3-2 Overview of Connecting Components to the 2410 Differential Refractometer

3.2 Making IEEE-488 Signal Connections

You can use the IEEE-488 bus to connect the 2410 refractometer to Waters or third-party data systems.

3.2.1 Connecting to a Waters Data System Using the IEEE-488 Bus

You can use the IEEE-488 bus to connect the 2410 refractometer to a W aters data system in an y one of the following conﬁgurations (see Figure 3-3, Figure 3-4, and Figure 3-5):

• Millennium Chromatography Manager through the busLAC/E™ card installed on the

computer (Figure 3-3)

Making IEEE-488 Signal Connections 3-3

• Waters 845 or 860 system through a LAC/E module (Figure 3-4)

• Waters 2690 Separations Module as part of an Alliance system (Figure 3-5).

Bus LAC/E or Network LAC/E Card

Millennium

Chromatography

Manager

IEEE-488 Cables

IEEE-488

Connector

600 Series

Pump

717plus

Autosampler

2410

Refractometer

Figure 3-3 Waters Millennium System IEEE-488 Connections

IEEE-488 Connector

IEEE-488

Cable

IEEE-802.3

Ethernet Connector

Thin Wire

Ethernet Cable

600 Series

Pump

IEEE-488

Cables

717plus

Autosampler

Figure 3-4 Waters 845/860 System IEEE-488 Connections

3-4 Making Signal Connections

LAC/E Module

ExpertEase 845/860

Workstation

2410

Refractometer

Millennium

Chromatography

Manager

Bus LAC/E or Network LAC/E Card

IEEE-488 Cables

2690

Separations

Module

Figure 3-5 Waters Alliance System IEEE-488 Connections

IEEE-488 Connectors

2410

Refractometer

Setting the IEEE-488 Address

Like all other IEEE-488 devices, the 2410 refractometer requires a unique IEEE-488 address to be recognized by an IEEE-488 controller, such as a Millennium Chromatography Manager , b usLA C/E module, or an Alliance™ or PowerLine™ System Controller.

The factory-set default IEEE-488 address for the 2410 differential refractometer is 10. To change the IEEE-488 address:

1. Press 2nd Func, Clear, Clear, then press Enter. The value diag is displayed.

2. Press 2nd Func, 6, Enter.

3. Enter the number corresponding to the desired IEEE-488 address, then press Enter.

Note: IEEE-488 addresses must be unique for each instrument in an HPLC system and must be between 2 and 29. Your HPLC system may require that the IEEE-488 address for the 2410 refractometer be greater than that for other devices in the system. Consult your data system or controller operator's manual for more information on IEEE-488 communications.

4. To exit the diagnostic functions, press 2nd Func, Clear, then press Enter.

Making Inject Start Signal Connections

When you are using an IEEE-488 data system with the 2410 differential refractometer, the data system or controller must receive an inject start signal from the autosampler or manual injector to initiate the data collection and time-based programs.

Making IEEE-488 Signal Connections 3-5

Note: Depending on your system conﬁguration, the inject start signal can be transmitted through the IEEE-488 interface or the analog-out/event-in connectors on the 2410 refractometer rear panel. For information on non-IEEE-488 connections, see Section 3.3, Making Non-IEEE-488 Signal Connections.

Table 3-2 summarizes the inject start connections for different system conﬁgurations.

Note: If multiple devices in your system require an inject start signal, connect trigger wires from the same (inject out) terminal on the injector to each device.

Table 3-2 Waters 2410 Refractometer Inject Start Connections

Inject Start Output Source

Waters 715, 717, and 717plus, and 2690 Separations Module, on the IEEE-488 bus

W aters 715, 717, and 717plus not on the IEEE-488 bus

W aters 2690 Separations Module not on the IEEE-488 bus

Waters 712 Autosampler Chart Mark and Ground

Waters manual injector, or third-party manual injector or autosampler

IEEE-488 interface (see Section 3.2.1, Connecting to a Waters Data System Using the IEEE-488 Bus)

Note: If you are using the Waters 845 or 860 Data System, you must program the multi-method to Start By LAC/E (refer to the ExpertEase Reference Guide for details).

Chart Mark and Ground

Chart Mark and Ground or Auto Zero and Ground

Chart Mark and Ground

Inject Start Input Connection

(on the 2410 Refractometer)

3-6 Making Signal Connections

3.2.2 Connecting to a Waters PowerLine System Controller

To connect the 2410 refractometer to a Waters PowerLine system controller, use the IEEE-488 interface cables as shown in Figure 3-6.

Each ﬂuid-handling unit is conﬁgured with either of the following:

• Integrated manual injector (built in as part of the drawer or shelf unit)

• Externally connected manual injector or autosampler

PowerLine

Controller

(600 Series Solvent

IEEE-488

Cable

Delivery System or

2690 Separations

Module)

717plus

Autosampler

Figure 3-6 Waters PowerLine System Controller IEEE-488 Connections

3.2.3 Connecting to a Manual Injector

If you are using a manual injector with your IEEE-488 system, connect the signal cables from the rear panel connector on the 2410 refractometer to the injector as indicated in Table 3-3.

Table 3-3 Waters 2410 Connections to a Manual Injector

2410 Refractometer

(Connector B)

Chart Mark + (red) One set of spade lug Chart Mark terminals

(the Waters injector includes two pairs of

Chart Mark – (black)

For information on injection trigger signals from a manual injector, see Section 3.3.5, Connecting Injection Trigger Signals.

cables that are functionally identical)

2410

Refractometer

Manual Injector

Making IEEE-488 Signal Connections 3-7

3.3 Making Non-IEEE-488 Signal Connections

To connect the 2410 refractometer to instruments that lack an IEEE-488 bus, you use the analog-out/event-in (I/O) connectors on the rear panel (Figure 3-7). Figure 3-7 shows the two I/O connectors (and their corresponding pin-outs) on the 2410 refractometer rear panel. Table 3-4 describes the functions of each connector.

This section describes signal connections between the 2410 refractometer rear panel analog-out/event-in connectors and the following:

• Waters 2690 Separations Module (used independently of the IEEE-488 interface)

• Waters 745/745B/746 Integrator

• Chart recorder

• Waters SAT/IN module

• Waters or other manual injector

• Other manufacturer’s integrator or A/D interface device

Caution: To avoid electrical shock, power off the 2410 refractometer before making any electrical connections.

Attention: To meet the regulatory requirements of immunity from external electrical

STOP

disturbances that may affect the performance of this instrument, do not use cables longer than 9.8 feet (3 meters) when you make connections to the analog-out/event-in connectors. In addition, ensure you always connect the shield of the cable to ground at one instrument only.

3-8 Making Signal Connections

A (Inputs and Outputs)

B (Inputs and Outputs)

1 Auto Zero + 2 Auto Zero – 3 Chassis Ground 4 Purge In + 5 Purge In – 6 Chassis Ground 7 Recorder Out +

8 Recorder Out – 9 Chassis Ground 10 Compressed Out + 11 Compressed Out – 12 Chassis Ground

1 Chart Mark + 2 Chart Mark – 3 Chassis Ground 4 Polarity 1 + 5 Polarity 1 – 6 Chassis Ground 7 Polarity 2 + 8 Polarity 2 – 9 Chassis Ground 10 Integrator Out + 11 Integrator Out – 12 Chassis Ground

Figure 3-7 Waters 2410 Rear Panel Analog-Out/Event-In Connectors

Table 3-4 describes the functions of the 2410 refractometer analog-out/event-in connectors.

Table 3-4 Waters 2410 Analog-Out/Event-In Connections

Signal Connections Description

Chart Mark Polarity 1 and 2

Accept TTL-level (0 to +5 V) or contact closure

signals from an external instrument Auto Zero Purge

Recorder Out Sends a ±2 V (full scale) signal to a chart recorder

Integrator Out Sends a ±2 V (full scale) signal to an integrator or

computer Compressed Out Sends a compressed (logarithmic) 0 to +10 mV

maximum output signal to a chart recorder or

integrator

Making Non-IEEE-488 Signal Connections 3-9

3.3.1 Connecting to a Stand-Alone 2690 Separations Module

Note: When you use the 2690 Separations Module as the system controller on the IEEE-488 bus, follow the instructions for connecting to a Waters PowerLine system (see Section 3.2.2, Connecting to a Waters PowerLine System Controller).

When you use the 2690 Separations Module as a stand-alone controller (not on the IEEE-488 bus or under Millennium software control), you can make the following signal connections using the 2410 refractometer analog-out/event-in connectors:

• Auto zero on inject

• Chart mark on inject

• Both chart mark and auto zero on inject

Generating Auto Zero on Inject

To generate the auto zero function on the 2410 refractometer at the start of an injection from the 2690 Separations Module, make the connections shown in Table 3-5 and Figure 3-8.

Table 3-5 Auto Zero Connections Between the 2690 Separations Module

and the 2410 Refractometer

2690 Separations Module

(Connector B)

Pin 1 Inject Start Pin 1 Auto Zero +

Pin 2 Inject Start Pin 2 Auto Zero –

3-10 Making Signal Connections

2410 Refractometer

(Connector A)

Waters 2410 Refractometer

Connector A

Waters 2690

Connector B

Inject Start Inject Start

Ground Stop Flow+ Stop Flow–

Hold Inject 1+ Hold Inject 1– Hold Inject 2+ Hold Inject 2–

Ground

Chart Out+ Chart Out–

Red

Black

1 2 3 4 5 6 7 8

9 10 11 12

1 Auto Zero+ 2 Auto Zero– 3 Chassis Ground 4 Purge In+ 5 Purge In– 6 Chassis Ground 7 Recorder Out+ 8 Recorder Out–

9 Chassis Ground 10 Compressed Out+ 11 Compressed Out– 12 Chassis Ground

TP01527

Figure 3-8 Auto Zero Connections Between the 2690 Separations Module

and the 2410 Refractometer

Generating Chart Mark on Inject

To generate the chart mark function on the 2410 refractometer at the start of an injection from the 2690 Separations Module, make the connections shown in Table 3-6 and Figure 3-9.

Table 3-6 Chart Mark Connections Between the 2690 Separations Module and the

2410 Refractometer

2690 Separations Module

(Connector B)

Pin 1 Inject Start Pin 1 Chart Mark +

Pin 2 Inject Start Pin 2 Chart Mark –

2410 Refractometer

(Connector B)

Making Non-IEEE-488 Signal Connections 3-11

Waters 2410 Refractometer

Connector B

Waters 2690

Connector B

Inject Start

Ground

Stop Flow+

Stop Flow– Hold Inject 1+ Hold Inject 1– Hold Inject 2+ Hold Inject 2–

Ground Chart Out+ Chart Out–

10 11 12

Red

1 2 3 4 5 6 7 8 9

Black

1 Chart Mark+ 2 Chart Mark– 3 Chassis Ground 4 Polarity 1+ 5 Polarity 1– 6 Chassis Ground 7 Polarity 2+ 8 Polarity 2–

9 Chassis Ground 10 Integrator Out+ 11 Integrator Out– 12 Chassis Ground

TP01527

Figure 3-9 Chart Mark Connections Between the 2690 Separations Module

and the 2410 Refractometer

Generating Chart Mark and Auto Zero

To generate both a chart mark and an auto zero signal from the 2690 Separations Module to the 2410 refractometer, make the connections shown in Table 3-7 and Figure 3-10.

Table 3-7 Chart Mark and Auto Zero Connections Between the 2690 Separations Module

and the 2410 Refractometer

2690 Separations

Module

(Connector B)

Pin 1 Inject Start Pin 1 Auto Zero + Pin 1 Chart Mark +

Pin 2 Inject Start Pin 2 Auto Zero – Pin 2 Chart Mark –

3-12 Making Signal Connections

2410 Refractometer

(Connector A)

2410 Refractometer

(Connector B)

Waters 2690

Connector B

Inject Start Inject Start

Ground Stop Flow+ Stop Flow–

Hold Inject 1+ Hold Inject 1– Hold Inject 2+ Hold Inject 2–

Ground Chart Out+ Chart Out–

10 11 12

Waters 2410 Refractometer

1 2 3 4 5 6 7 8 9

Red

Black

Connector A

1 Auto Zero+ 2 Auto Zero– 3 Chassis Ground 4 Purge In+ 5 Purge In– 6 Chassis Ground 7 Recorder Out+ 8 Recorder Out–

9 Chassis Ground 10 Compressed Out+ 11 Compressed Out – 12 Chassis Ground

Waters 2410 Refractometer

Connector B

Figure 3-10 Chart Mark and Auto Zero Connections Between

the 2690 Separations Module and the 2410 Refractometer

1 Chart Mark+ 2 Chart Mark– 3 Chassis Ground 4 Polarity 1+ 5 Polarity 1– 6 Chassis Ground 7 Polarity 2+ 8 Polarity 2– 9 Chassis Ground 10 Integrator Out+ 11 Integrator Out– 12 Chassis Ground

TP01527B

3.3.2 Connecting to the Waters 745/745B/746 Data Module

To send an integrator analog output signal (–2V to +2V) from the 2410 refractometer to the Waters 745/745B/746 Data Module, make the connections shown in Table 3-8 and Figure 3-11.

Table 3-8 Analog Output Connections to a 745/745B/746 Data Module

745/745B/746 Rear Panel

Connectors

CHA (+) Pin 10 Integrator Out+ (red)

2410 Refractometer

(Connector B)

Making Non-IEEE-488 Signal Connections 3-13

Table 3-8 Analog Output Connections to a 745/745B/746 Data Module (Continued)

745/745B/746 Rear Panel

Connectors

2410 Refractometer

(Connector B)

CHA (–) Pin 11 Integrator Out– (black)

Shield not used; tape back to prevent shorting.

Note: If you use the Waters 745/745B/746 with a chart recorder, use separate channels for plotting and integration. Otherwise, changes in chart recorder attenuation may affect the integration of the peaks.

Note: If you use another manufacturer’s integrator or A/D device, you may need to connect the Chassis Ground (pin 12) to the 2410 detector’s Integr ator Out– (blac k lead) or an equivalent connection.

Waters 2410 Refractometer

Connector B

Red

Black

+ –

CHA

Waters 745/745B/746

Connector or Other

A/D Interface Device

1 Chart Mark+ 2 Chart Mark– 3 Chassis Ground 4 Polarity 1+ 5 Polarity 1– 6 Chassis Ground 7 Polarity 2+ 8 Polarity 2– 9 Chassis Ground 10 Integrator Out+ 11 Integrator Out– 12 Chassis Ground

Figure 3-11 Connections to a Waters 745/745B/746 Data Module

3-14 Making Signal Connections

TP01486

3.3.3 Connecting to a Chart Recorder

To send an analog output signal from the 2410 refractometer to a chart recorder, make the connections shown in Table 3-9 and Figure 3-12.

Table 3-9 Analog Output Connections to a Chart Recorder

Chart Recorder

Connectors

2410 Refractometer

(Connector A)

Pen 1 (+) Pin 7 Recorder Out + (red)

Pen 1 (–) Pin 8 Recorder Out – (black)

Shield not used; tape back to prevent shorting.

Waters 2410 Refractometer

Connector A

Red

Black

+ – –

Chart Recorder

Connectors

Auto Zero +

Auto Zero –

Chassis Gnd

Purge In +

4 5

Purge In – Chassis Gnd

Recorder Out +

7 8

Recorder Out –

Chassis Gnd

Compressed Out +

Compressed Out –

Chassis Gnd

TP01488

Figure 3-12 Analog Output Connections to a Chart Recorder

Performing Chart Mark with the Chart Recorder

If you are controlling the 2410 refractometer from the 745/745B/746 data module and you want to send a chart mark pulse to the chart recorder at the start of each run, connect the external device (system controller, autosampler, or manual injector) to the 2410 refractometer Chart Mark screw terminals, as described in Section 3.3.2, Connecting to the Waters 745/745B/746 Data Module.

Making Non-IEEE-488 Signal Connections 3-15

3.3.4 Connecting to the Waters 845/860 ExpertEase System

T o send an inte grator analog output signal (–2V to +2V) from the 2410 refractometer to an 845/860 ExpertEase System (through a two-channel SAT/IN module), make the connections shown in Table 3-10 and Figure 3-13.

Table 3-10 Analog Output Connections to the Bus SAT/IN Module

SAT/IN Module

Connector

CHANNEL 1 or CHANNEL 2

2410 Refractometer

(Connector B)

Pin 10 Integrator Out + (white)

Pin 11 Integrator Out – (black)

See Section 3.2.1, Connecting to a Waters Data System Using the IEEE-488 Bus, Figure 3-4, for information on connecting the remaining components of the 845/860 Data System.

Waters 2410 Refractometer

Connector B (Inputs and Outputs)

1 Chart Mark +

1 2

2 Chart Mark –

3 Chassis Gnd

4 Polarity 1 +

5 Polarity 1 –

Waters Bus SAT/IN Module

CHANNEL 1 CHANNEL 2

EVENTS

CH1

CH2

IN INOUT OUT

+ – + – + – + –

1 2 3 4 5 6 7 8

CH1CH

Red

White

Black

6 Chassis Gnd

7 Polarity 2 +

8 Polarity 2 –

9 Chassis Gnd

10 Int Out +

11 Int Out –

12 Chassis Gnd

TP01484

Figure 3-13 Analog Output Connections to the Bus SAT/IN Module

3.3.5 Connecting Injection Trigger Signals

The 2410 refractometer accepts the following injection trigger signals from a manual injector:

• Auto zero signal to automatically adjust the zero offset of the 2410 refractometer each time the injector makes an injection

• Chart mark (inject start) signal from a contact closure signal with each injection

3-16 Making Signal Connections

Each time the 2410 refractometer receives a signal from a manual injector, it performs the corresponding auto zero or chart mark function.

To send an auto zero or chart mark signal from a manual injector to the 2410 refractometer, make the connections shown in Table 3-11 and Figure 3-14 and Table 3-12 and Figure 3-15.

Table 3-11 Auto Zero Connections to a Manual Injector

2410 Refractometer

(Connector A)

Manual Injector Connector

Pin 1, Auto Zero + (red) Two spade lug terminal connectors

(both cables may be functionally

Pin 2, Auto Zero – (black)

Waters 2410 Refractometer

Connector A

1 Auto Zero + 2 Auto Zero – 3 Chassis Ground 4 Purge In + 5 Purge In – 6 Chassis Ground 7 Recorder Out + 8 Recorder Out –

9 Chassis Ground 10 Compressed Out + 11 Compressed Out – 12 Chassis Ground

identical) or similar connectors.

Manual Injector

Figure 3-14 Auto Zero Connectionto a Manual Injector

Making Non-IEEE-488 Signal Connections 3-17

Table 3-12 Chart Mark Connections to a Manual Injector

2410 Refractometer

(Connector B)

Manual Injector Connector

Pin 1, Chart Mark + (red) Two spade lug terminal connectors

(both cables may be functionally

Pin 2, Chart Mark – (black)

Waters 2410 Refractometer

Connector B

1 Chart Mark+ 2 Chart Mark– 3 Chassis Ground 4 Polarity 1+ 5 Polarity 1– 6 Chassis Ground 7 Polarity 2+ 8 Polarity 2– 9 Chassis Ground 10 Integrator Out+ 11 Integrator Out– 12 Chassis Ground

identical) or similar connectors.

Manual Injector

Figure 3-15 Chart Mark Connections to a Manual Injector

3.3.6 Polarity Connections

The Polarity 1 and 2 contact closures on the rear panel of the 2410 refractometer determine the peak polarity of the output signal according to the following conditions (negati v e polarity results in negative, or inverted, peaks):

• Polarity 1 serves as a positive/negative input

• Polarity 2 serves as an external input (Polarity 1) enable

• When Polarity 2 is open (not connected), the +/– key on the 2410 front panel or an IEEE-488 connected data system (such as the Millennium Chromatography Manager or PowerLine) determines the polarity (see Section 5.2.5, Polarity Guidelines).

3-18 Making Signal Connections

• When Polarity 2 is closed (connected to an instrument), Polarity 1 determines peak polarity. Polarity 1 open (disconnected) generates negative polarity. Polarity 1 closed (connected) generates positive polarity.

Table 3-13 summarizes the polarity options.

Table 3-13 Polarity Options

Polarity 2 Polarity 1 Recorder Polarity

Open Open No Effect

Open Closed No Effect

Closed Open Negative (Inverted)

Closed Closed Unchanged

3.4 Connecting the External Column Heaters

The W aters 2410 Dif ferential Refractometer can control up to two optional e xternal column heaters through the EXT 1 and EXT 2 ports l on the rear panel of the detector (Figure 3-16). The ports are standard 9-pin DIN connectors.

Connecting the External Column Heaters 3-19

Waters 2410 Refractometer

Rear Panel

External

Column

Heater

Ports

EXT 2 EXT 1

Figure 3-16 2410 Refractometer External Column Heater Ports

3-20 Making Signal Connections

Chapter 4

Preparing Solvents

4.1 Common Solvent Problems............................... 4-1

4.2 Selecting a Solvent ............................................ 4-2

4.3 Solvent Degassing ............................................. 4-4

Preparing Solvents

Proper solvent selection and preparation are critical in differential refractometry to prev ent baseline changes such as drift, noise, or an erratic baseline. This chapter presents information on:

• Common solvent problems

• Selecting a solvent

• Solvent degassing

Caution: To avoid chemical hazards, always observe good laboratory practices when handling solvents. Refer to the Material Safety Data Sheets shipped with solvents for handling information.

4.1 Common Solvent Problems

The 2410 refractometer measures changes in the concentration of the solution ﬂowing through the sample side of the ﬂow cell (see Section 1.2, Theory of Operation). Howe v er, factors other than the presence of dissolved sample molecules can affect a solution’s refractive index. Common problems include:

• Changes in temperature

• Changes in pressure

• Contaminants

• Separation of mixed solvents

• Outgassing of dissolved gases

Common Solvent Problems 4-1

4.2 Selecting a Solvent

An ideal solvent for your analysis:

• Has good solubility characteristics for your application

• Has a signiﬁcantly different refractive index (RI) than the sample components

• Gives satisfactory baseline noise performance

• Provides optimum optical sensitivity characteristics

Solvent Quality

Use spectral-grade or HPLC-grade solvents to ensure:

• Reproducible results

• Operation with minimal instrument maintenance

• Minimal optical interference

A dirty or impure solvent can cause:

• Baseline noise and drift

• Plugged columns

• Blockages in the ﬂuidic path

Preparation Checklist

The following solvent preparation guidelines help to ensure stable baselines and good resolution:

• Filter solvents with a 0.45-µm ﬁlter.

• Degas and/or sparge the solvent.

• Stir the solvent.

• Keep solvents in a place free from drafts and shock.

Water

Use water only from a high-quality water puriﬁcation system. If the water system does not provide ﬁltered water, ﬁlter it through a 0.45-µm membrane ﬁlter before use.

Buffers

When you use buffers, dissolve salts ﬁrst, adjust the pH, then ﬁlter to remove undissolved material.

4-2 Preparing Solvents

Tetrahydrofuran (THF)

When you use unstabilized THF, ensure that your solvent is fresh. Previously opened bottles of THF contain peroxide contaminants, which cause baseline drift.

Caution: THF contaminants (peroxides) are potentially explosive if concentrated or taken to dryness.

Refractive Indices of Common Solvents

Table 4-1 lists the refractive indices for some common chromatographic solvents. Use this table to verify that the solvent you intend to use for your analysis has an RI signiﬁcantly different from the sample components.

Table 4-1 Refractive Indices of Common Solvents

Solvent RI Solvent RI

Fluoroalkanes 1.25 Tetrahydrofuran (THF) 1.408

Hexaﬂuoroisopropanol (HFIP) 1.2752 Amyl alcohol 1.410

Methanol 1.329 Diisobutylene 1.411

Water 1.33 n-Decane 1.412

Acetonitrile 1.344 Amyl chloride 1.413

Ethyl ether 1.353 Dioxane 1.422

n-Pentane 1.358 Ethyl bromide 1.424

Acetone 1.359 Methylene chloride 1.424

Ethanol 1.361 Cyclohexane 1.427

Methyl acetate 1.362 Ethylene glycol 1.427

Isopropyl ether 1.368 N,N-dimethyl formamide

(DMF)

Ethyl acetate 1.370 N,N-dimethyl acetamide

(DMAC)

1-Pentene 1.371 Ethyl sulﬁde 1.442

Selecting a Solvent 4-3

1.428

1.438

Table 4-1 Refractive Indices of Common Solvents (Continued)

Solvent RI Solvent RI

Acetic acid 1.372 Chloroform 1.443

Isopropyl chloride 1.378 Ethylene dichloride 1.445

Isopropanol 1.38 Carbon tetrachloride 1.466

n-Propanol 1.38 Dimethyl sulfoxide (DMSO) 1.477

Methylethylketone 1.381 Toluene 1.496

Diethyl amine 1.387 Xylene ~1.50

n-Propyl chloride 1.389 Benzene 1.501

Methylisobutylketone 1.394 Pyridine 1.510

Nitromethane 1.394 Chlorobenzene 1.525

1-Nitropropane 1.400 o-Chlorophenol 1.547

Isooctane 1.404 Aniline 1.586

Cyclopentane 1.406 Carbon disulﬁde 1.626

4.3 Solvent Degassing

Using degassed solvents is the most important step in solvent preparation. Degassing provides:

• Stable baselines and enhanced sensitivity

• Reproducible retention times

• Stable pump or solvent delivery system operation

This section presents information on the solubility of gases, solvent degassing methods, and solvent degassing considerations.

4-4 Preparing Solvents

4.3.1 Gas Solubility

The amount of gas that can dissolve in a given volume of liquid depends on:

• The chemical afﬁnity of the gas for the liquid

• The temperature of the liquid

• The pressure applied to the liquid

Changes in the composition, temperature, or pressure of the mobile phase can lead to outgassing.

Effects of Intermolecular Forces

Nonpolar gases (N2, O2, CO2, He) are more soluble in nonpolar solvents than in polar solvents. Generally, a g as is most soluble in a solv ent with intermolecular attracti v e forces similar to those in the gas (“like dissolves like”).

Effects of Temperature

T emperature af fects the solubility of gases. If the dissolution is e xothermic, the solubility of the gas decreases when you heat the solvent. If the dissolution is endothermic, the solubility increases when you heat the solvent. For example, the solubility of He in H temperature, but the solubility of He in benzene increases with an increase in temperature.

Effects of Partial Pressure

The mass of gas dissolved in a given v olume of solvent is proportional to the partial pressure of the gas in the vapor phase of the solvent. If you decrease the partial pressure of the gas, the amount of that gas in solution also decreases.

O decreases with an increase in

4.3.2 Solvent Degassing Methods

Solvent degassing helps you attain a stable baseline and also improves reproducibility and pump performance.

There are three common methods used to degas solvents:

• Sparging with helium

• Reducing pressure by vacuum

• Sonication

These methods may be used individually or in combination. Vacuum sonication followed by sparging is the most effective technique for most solvents.

Solvent Degassing 4-5

Sparging

Sparging removes gases from solution by displacing dissolved gases in the solvent with a less soluble gas, usually helium. Well-sparged solvent improves pump performance. Helium sparging brings the solvent to a state of equilibrium, which may be maintained by slow sparging or by keeping a blanket of helium over the solvent. Blanketing inhibits reabsorption of atmospheric gases.

Note: Sparging may change the composition of mixed solvents.

Vacuum Degassing

The in-line vacuum degasser operates on the principle of Henry’s Law to remove dissolved gases from the solvent. Henry’s Law states that the mole fraction of a gas dissolved in liquid is proportional to the partial pressure of that gas in the vapor phase above the liquid. If the partial pressure of a gas on the surface of the liquid is reduced, for example, by evacuation, then a proportional amount of that gas comes out of solution.

Note: Vacuum degassing may change the composition of mixed solvents.

Sonication

Sonication with high energy sound waves drives energy into the solvent and causes the submicron-sized “bubbles” of gas to aggregate. As the gas bubbles aggregate, they become large enough to ﬂoat out of the solvent and dissipate. Sonication alone degasses 4 liters of solvent in approximately 22 minutes.

4.3.3 Solvent Degassing Considerations

Select the most efﬁcient degassing operation for your application. To remove dissolved gas quickly, consider the following:

Sparging

Helium sparging results in a more stable detector baseline and better detector sensitivity than sonication, and prevents reabsorption of atmospheric gases. Use this method to retard oxidation when you are using THF or other peroxide-forming solvents.

4-6 Preparing Solvents

Vacuum Degassing

The longer a solvent is exposed to the vacuum, the more dissolved gases are removed. Two factors affect the amount of time the solvent is exposed to the vacuum:

• Flow rate – At low ﬂow rates, most of the dissolved gas is removed as the solvent passes through the vacuum chamber. At higher ﬂow rates, lesser amounts of gas per unit volume of solvent are removed.

• Surface area of the degassing membrane – The length of the degassing membrane is ﬁxed in each vacuum chamber. To increase the length of membrane, you can connect two or more vacuum chambers in series.

The in-line degasser is available as an option or factory-installed in the Waters® 2690 Separations Module, XE model.

When you are using the 2690 Separations Module with the 2410 refractometer, set the in-line degasser to “continuous” degas mode.

Select the most efﬁcient degassing operation for your application. To remove dissolved gas quickly, consider the following degassing considerations.

Sonication Plus Vacuum

Sonication combined with vacuum degasses solvent very quickly. This technique is less likely to change the composition of mixed solvents because the mixed solvents are held under vacuum for only a short time (less than a minute is usually sufﬁcient).

Caution: Do not apply vacuum to the brown glass bottles in which solvent is shipped. There is a high risk of implosion under these conditions. Use a thick-walled container designed for vacuum applications.

Solvent Degassing 4-7

4-8 Preparing Solvents

Chapter 5

Using the 2410 Refractometer

5.1 Using the Front Panel........................................ 5-1

5.2 Selecting Parameter Values................................ 5-9

5.3 Starting Up the 2410 Refractometer................ 5-13

5.4 Shutting Down the 2410 Refractometer .......... 5-15

Using the 2410 Refractometer

This chapter covers:

• Using the Front Panel

• Selecting Parameters

• Routine Startup

• Powering Off

Stand-Alone Mode

You can use the Waters 2410 Differential Refractometer as a stand-alone module in conjunction with a pump, injector, column, and a recorder or integrator. In this conﬁguration, you control the 2410 refractometer from its front panel. To use the 2410 refractometer in this way, follow the instructions provided in this chapter.

Remote Control Mode

You can use the 2410 refractometer as part of a system conﬁgured and controlled by a Waters data system, such as the Millennium Chromatography Manager, or a Waters PowerLine system controller (including the 2690 Separations Module). If you set up the 2410 refractometer in this way, follow the instructions in the appropriate data system or controller operator’s guide to set parameters and to control the 2410 refractometer. When the 2410 refractometer is operating in remote control mode, you can continue to run diagnostics from the front panel (see Section 7.3, Diagnostics).

Note: Read Chapter 4, Preparing Solvents, before using the 2410 refractometer.

5.1 Using the Front Panel

The 2410 refractometer front panel consists of a four-character LED display, eight LED parameter indicators, and a keypad (Figure 5-1).

Using the Front Panel 5-1

Four-Character LED Display

The four-character LED display shows parameter and input values. To display the value of a parameter, press the appropriate parameter key (Figure 5-1 and Table 5-1). The parameter is displayed (in the four-character LED), and its corresponding indicator remains illuminated until you select another parameter.

Four-Character

LED Display

Parameter

Indicator

LEDs

C Int °C

Ext 1

Ext 2

Remote

% Full Scale

Set

Mark Purge

2nd

Function

Filter

+/−

0 Clear

Auto Zero

Sens

Scale

Factor

Enter

Figure 5-1 Display, LED Indicators, and Keypad

5-2 Using the 2410 Refractometer

LED Parameter Indicators

Eight parameter indicator LEDs are located above and to the right of the numeric keypad (Figure 5-1). When you select a parameter from those described in Table 5-1, the corresponding LED illuminates.

Table 5-1 Indicator LED Functions

Parameter Indicator Description

Ext 1 °C Ext 2 °C

Int °C Illuminates when the temperature of the internal oven is

Remote Illuminates when the 2410 refractometer is under the control

% Full Scale Illuminates when the chart recorder output of the 2410

Sens Illuminates when the current sensitivity setting is displayed in

Scale Factor Illuminates when the current scale factor setting is displayed

2nd Func Illuminates when the 2nd Func key is activated (after

Illuminates when the current settings for the external column heaters are displayed in the four-character LED; also illuminates when you are changing the settings for the external column heaters.

displayed in the four-character LED; also illuminates when you are changing the temperature.

of a remote controller.

differential refractometer (as a percent referenced to 10 mV) is displayed in the four-character LED.

the four-character LED; also illuminates when you are changing the sensitivity.

in the four-character LED; also illuminates when you are changing the scale factor.

pressing the 2nd Func key); stays illuminated for ﬁve seconds, waiting for you to press the key whose secondary function you want to access.

Using the Front Panel 5-3

5.1.1 Keypad Functions

You use the keypad (see Figure 5-1) to:

• View the current settings or values of parameters

• Select or enter new parameter settings

• Activate speciﬁc operational functions

• Perform diagnostic tests

Some keys scroll through a series of available values. To scroll through the values, you press the key repeatedly until the desired value appears, then release the key and press Enter.

Primary and Secondary Functions

Each key is labeled with a primary function. When you press a key, the function named on the key is performed. For example, press the Sens key and you are prompted to enter a sensitivity value.

Most keys also have a secondary function, shown in smaller type (on the key) above the primary function or number. To use a secondary function, press the 2nd Func key, then the k ey labeled with the secondary function. For example, press 2nd Func, then Purge to set the 2410 refractometer to purge mode.

Table 5-2 describes how to use the primary and secondary functions.

Table 5-2 Keypad Functions

Key Description

Remote

% Full Scale

5-4 Using the 2410 Refractometer

Primary

% Full Scale – Displays the chart recorder (REC) output (in millivolts) of the 2410 refractometer as a percent referenced to 10 mV. When the display reads 0001, the output is 1 percent of 10 mV, or 0.1 mV. A value of 0100 means that the output is 100 percent, or 10.0 mV.

Secondary

Remote – When the 2410 refractometer is under active control by a data system or system controller through the IEEE-488 interface, the Remote indicator is illuminated.

Table 5-2 Keypad Functions (Continued)

Key Description

Sens

Scale Factor

Enter

Clear

2nd

Func

0-9

Sens – Displays the current or selects a new sensitivity value. Repeated pressing of the key scrolls through the allowable values between 1 (least sensitive) and 1024 (most sensitive); or, you can enter a numeric value (only powers of 2 are allowed, such as 2, 4, 8, 16, 32, and so on). The def ault value is 4. For more information, see Section 5.2.1, Sensitivity Guidelines.

Scale Factor – Selects a scale factor, with allowable values between 1 and 100. The default value is 20.

Scale factor affects the magnitude of the peaks on the chart recorder output only. Scale factor does not affect integrator or IEEE-488 data output; it functions as an attenuator for the chart recorder output.

See Section 5.2.2, Scale Factor Guidelines, for more information.

Enter – Saves parameter settings in the memory of the 2410 refractometer.

Clear – Erases unsaved parameter entries.

2nd Func – Accesses secondary functions. Pressing the 2nd Func key

activates secondary functions. Stays active for ﬁve seconds during which the indicator LED located to the right of the Enter key is illuminated.

Primary

0-9 – Used to enter values for parameters. After entering a numeric value, press Enter.

Using the Front Panel 5-5

Table 5-2 Keypad Functions (Continued)

Key Description

Ext 1 °C

Ext 2 °C

Int °C

Secondary

Ext1 °C and Ext2 °C – Display the temperature setting of a selected external column heater in degrees Celsius.

To change the temperature of a column heater:

1. Press 2nd Func followed by Ext1 °C or Ext2 °C. The current

temperature setting of the column heater appears in the display, and the corresponding indicator lights up.

2. Press 2nd Func, Set °C, enter the new temperature (ambient to 150 °C), then press Enter.

3. Press Clear to disable.

The value of 245.7 appears when no column heater is connected. Int °C –Displays the current temperature of the internal oven. This is the

value that ﬂashes on startup. Press Clear to stop it from ﬂashing. To change the temperature:

1. Press 2nd Func followed by Int °C. The temperature of the internal oven appears in the display, and the corresponding indicator lights up.

2. Press 2nd Func, Set °C, enter the new temperature (30 °C to 50 °C), then press Enter.

Note: It tak es several hours for the optics bench assembly to stabilize at the new temperature. Do not make a run until the temperature has stabilized; the changing temperature causes baseline drift.

Set °C

Set °C – Sets the temperature of a column heater or the internal oven. The range of allowable values (“set points”) for the internal oven is 30 to 50 °C; for the column heaters, it is 0 to 150 °C.

Note: The minimum stable set point is 5 °C above the ambient temperature.

To power off the column heater or internal oven:

1. Press 2nd Func followed by Ext1 °C, Ext2 °C, or Int °C (for either column heater or for the internal oven). The temperature of the column heater or oven appears in the display, and the corresponding indicator lights up.

2. Press 2nd Func, Set °C, Clear, then press Enter.

5-6 Using the 2410 Refractometer

Table 5-2 Keypad Functions (Continued)

Key Description

Filter

Auto Zero

Mark

+/–

Purge

Filter – Adjusts the time constant of the noise ﬁlter to achieve the optimum signal-to-noise ratio. Repeated pressing of the Filter key scrolls through the values 0.2, 1, 3, and 10. Press Enter when you reach the value you want. The default value is 1. For more information, see Section 5.2.3, Time Constant Guidelines.

Auto Zero – Adjusts the zero offset of the analog output to compensate for changes in baseline position. Use Auto Zero at any time, for example, before beginning a new run.

Mark – Sends a chart mark signal to the recorder or data module. The chart mark is always a 10 percent (of full scale) deﬂection in the positive direction, regardless of chart polarity.

+/– : Changes the chart polarity . Pressing the +/– key once shows the current setting in the four-character LED. Keeping the +/– key pressed alternates through + (POS) and – (NEG). When the display shows the polarity you want, press Enter.

Purge – Purges the reference and sample sides of the fluidic path with fresh solvent. Purging requires pressing Purge twice, once to start and then once to ﬁnish the purge. During the purge, the display shows the letters PgE.

Purge the ﬂuidic path whenever you change solvents or experience an unexpected loss in sensitivity due to excess noise or drift.

Viewing Parameter Values

To view the current value for a primary function parameter, press the key for the parameter whose value you want to see. To view the current value for a secondary function parameter, press 2nd Func, then press the key for the secondary function value you want to view.

Changing the Sensitivity or Scale Factor

To change a value for the Sens (sensitivity) or Scale Factor:

1. Press the key for the parameter whose value you want to change.

2. Select a new value by scrolling (Sens only) or by entering the value using the numeric keys.

Using the Front Panel 5-7

3. Press Enter to save the new value. If you enter an unacceptable value, the 2410 refractometer beeps and returns to the previous value.

Changing the Filter Value

To change the value for the ﬁlter:

1. Press the 2nd Func key.

2. Press the Filter key to view the current value.

3. Press the Filter key repeatedly to scroll to a new value.

4. Press Enter to save the new value. If you do not press Enter within 5 seconds or if you enter an unacceptable value, the 2410 refractometer beeps and returns to the previous value.

Changing the Oven or Column Heater Temperature

To change the temperature settings for the oven or the external column heaters:

1. Press the 2nd Func key, then press the key for the unit whose temperature you want to change (Ext 1 °C, Ext 2 °C, or Int °C).

2. Press the 2nd Func key, then press the Set °C key.

3. Enter a new temperature from the numeric keys (pressing Clear powers off the internal oven or column heater).

4. Press Enter to save the new temperature. If you enter an invalid temperature, the 2410 refractometer beeps and returns to the previous value.

Changing Polarity

To change output polarity:

1. Press the 2nd Func key, then press the +/– key.

2. Press the +/– key again to reverse the polarity.

3. Press Enter to save the new value.

Using Auto Zero, Mark, and Purge

To use Auto Zero, Mark, or Purge:

1. Press the 2nd Func key, then press the key for the function you want to access (Auto Zero, Mark, or Purge).

5-8 Using the 2410 Refractometer

2. Press Enter. When you perform the Auto Zero command, the letters AX appear on the display. When you perform the Mark command, the letters CH appear on the display. When you perform the Purge command, the letters PgE appear on the display.

To stop purging, press 2nd Func, Purge, then press Enter. The display returns to the function it displayed before the purge began.

5.2 Selecting Parameter Values

You can adjust the noise level, peak height, peak direction, and the temperatures of the internal oven and column heaters to optimize the performance of the 2410 refractometer. This section provides guidelines and considerations for selecting parameter values that are best suited to your application. The parameters are:

• Sensitivity (Sens key)

• Scale factor

• Time constant (Filter key)

• Temperature (Ext1 °C, Ext2 °C, Int °C, Set °C keys)

• Polarity (+/– key)

5.2.1 Sensitivity Guidelines

Sensitivity affects the magnitude of the output signal to an integrator or a recorder. Increasing the sensitivity (Sens) setting increases the resulting peak areas, but it also increases baseline noise and the response to environmental ﬂuctuations. In addition, an increase in sensitivity reduces the dynamic range over which the refractometer output is useful. Refer to Figure 5-2 for examples of the effects of varying the Sens setting on a chromatogram.

Selecting Parameter Values 5-9

Figure 5-2 Effects of Sensitivity Settings

5.2.2 Scale Factor Guidelines

At high sensitivities, the height of some peaks may be too great to ﬁt on a chart recorder. You can use the scale factor to reduce the plot proportionally. The scale factor affects the refractometer output only to the recorder.

A high scale factor setting results in a large plot, which may cause some peaks to go offscale. A small scale factor setting reduces the height and width of the plot, so small peaks may not be well deﬁned.

Scale factor settings:

• Reduce large peaks to ﬁt the chart recorder scale, but reduce smaller peaks as well.

• Have no effect on peak resolution, only amplitude.

To calculate an appropriate scale factor setting, use the equation:

where: %FS = the % Full Scale value displayed in the four-character LED display when the 2410 refractometer detects the largest peak (the % Full Scale display reads 100 for a 10 mV signal at the chart recorder output).

10 000,

----------------- -=

% FS

Sens = 4Sens = 16

5-10 Using the 2410 Refractometer

Integrator Output Considerations

The relationship between the sensitivity (Sens) setting (S), change in refractive index (∆n), and integrator output voltage (V) is expressed by the equation:

Integrator Out V() 200 S ∆n××=

The maximum change in refractive index (∆n) that the 2410 refractometer can optically measure is 5 × 10–3 RIU. The integrator output range is limited to ± 2 V full scale.

Chart Recorder Output Considerations

Use of the 2410 refractometer with both a an integrator and a chart recorder is possible because you can program the 2410 refractometer with an offset from 0 to 50 mV. The maximum voltage on the recorder output is always 2 V regardless of the sensitivity or scale factor setting; a display of 100% Full Scale on the 2410 front panel is equal to 10 mV.

When the detector output is through the recorder output terminals, you can adjust your plot with the 2410 refractometer scale factor function.

The relationship between the chart recorder output (in millivolts) to the difference in refractive index (∆n), the sensitivity setting (S), and the scale factor (SF) is expressed by the equation:

Recorder Output mV()2000 SF S ∆n×××=

Chart recorder output is limited to ±2 V full scale.

5.2.3 Time Constant Guidelines

The Filter parameter speciﬁes the ﬁlter time constant, which adjusts the response time of the noise ﬁlter. Adjusting the noise ﬁlter (time) allows you to achieve an optimum signal-to-noise ratio by reducing short-time noise.

Low filter time constant settings:

• Produce narrower peaks with minimum peak distortion and time delay

• Increase baseline noise

High filter time constant settings:

• Shorten and broaden peaks

• Decrease baseline noise

The default ﬁlter time constant setting of 1.0 second is appropriate for most applications.

Selecting Parameter Values 5-11

You can calculate an appropriate ﬁlter time constant using the equation:

TC = 0.2 × PW

where: TC = Time constant setting

PW = Peak width in seconds at half height of the narrowest peak

Figure 5-3 illustrates the effects of the time constant (Filter) settings on the signal.

Low Filter High Filter

Time Constant

Setting

Time Constant

Setting

Figure 5-3 Effects of Filter Time Constant Settings

5.2.4 Temperature Guidelines (Ext1 °C, Ext2 °C, Int °C)

The 2410 refractometer permits temperature ranges of 30 to 50 °C for the internal oven (Int °C key), and from 0 to 150 °C for the two external column heaters (Ext1 °C, Ext2 °C). The general operating temperature for the internal oven should be set about 5 °C above the ambient temperature for room temperature applications. This guards against drift caused by variations in the ambient temperature.

Be aware that higher temperature settings generally:

• Reduce the viscosity of the mobile phase

• Increase the solubility of the sample

• Increase mass transfer rates, improving column efﬁciency

• Decrease retention times

5-12 Using the 2410 Refractometer

• Make the system less susceptible to ﬂuctuations in ambient temperature

• Cause dissolved gases to come out of poorly degassed solvents, resulting in bubbles

Internal oven temperatures of 30 to 35 °C are satisfactory for most room-temperature applications. For best performance, the external column heater and the 2410 refractometer oven should be set to the same temperature.

5.2.5 Polarity Guidelines

The polarity key (+/–) inverts the direction of peaks. Samples detected with the 2410 refractometer can yield positive or negative peaks, depending on whether their RIs are greater than or less than the RI of the mobile phase. Polarity affects data sent over the analog output channels and the IEEE-488 interface. Polarity does not affect the % Full Scale display.

The default polarity setting is positive, that is, the polarity is unchanged. See also Section 3.3.6, Polarity Connections.

5.3 Starting Up the 2410 Refractometer

To start up the 2410 refractometer:

1. Press the On/Off switch located on the lower front right corner of the unit. While the 2410 refractometer performs internal tests, the four-character LED display ﬂashes all 8’s, goes blank for eight seconds, then displays a ﬂashing “–” in the rightmost slot of the four-character display.

2. If the startup diagnostics fail, one of the following is displayed in the four-character LED display:

• All blank, indicating that the 2410 refractometer has halted operation during diagnostic testing. Restart the instrument. If the instrument continues to fail, contact Waters Technical Service.

• An “E” in the leftmost slot, indicating an error condition. Contact Waters Technical Service

3. If the startup diagnostics are successful, the 2410 refractometer checks the integrity of the parameter values stored in battery-backed RAM. If the values are valid, the 2410 refractometer ﬂashes the internal oven setpoint stored in the RAM in the four-character LED display. The 2410 refractometer startup code calibrates its internal sensors while illuminating each LED indicator once in succession. When this calibration is ﬁnished, the 2410 refractometer begins to regulate the internal oven and external column heater temperatures to their setpoints, and ﬂashes the current internal oven temperature in the four-character LED display.

Starting Up the 2410 Refractometer 5-13

4. At this point, the startup sequence has run successfully, and the 2410 refractometer is ready for operation.

Note: Pressing Clear does not stop the four-character LED display from ﬂashing while the calibration sequence is in progress.

5. If the battery-backed RAM fails the integrity check (because of a low battery), the software resets the stored parameters to their default values. While the 2410 refractometer calibrates its internal sensors, the “–” continues to ﬂash in the four-character LED display and each LED indicator is illuminated once in succession. When the calibration completes, the % Full Scale parameter is activated and displayed, non-ﬂashing, on the four-character LED display, and the 2410 refractometer is ready for operation.

6. Once the 2410 refractometer startup diagnostics and tests are complete, power on any peripheral equipment.

7. Allow the 2410 refractometer to warm up for 24 hours before operating it.

Remote Mode

The 2410 refractometer operates in remote mode when it is under active control by a system controller through the IEEE-488 interface. You can conﬁgure remote control of the 2410 refractometer with Waters systems such as the:

• Millennium Chromatography Manager (see Section 3.2.1, Connecting to a Waters Data System Using the IEEE-488 Bus)

• 600E Multisolvent Delivery System (see Section 3.2.2, Connecting to a Waters PowerLine System Controller)

• 745/745B/746 Data Module (see Section 3.3.2, Connecting to the Waters 745/745B/746 Data Module)

• 845/860 Data Control System (see Section 3.3.4, Connecting to the Waters 845/860 ExpertEase System)

• 2690 Separations Module (see Section 3.3.1, Connecting to a Stand-Alone 2690 Separations Module).

Changing Solvents

Caution: To avoid chemical hazards, always observe safe laboratory practices when you are operating your system. Refer to the Material Safety Data Sheets shipped with solv ents for handling information.

5-14 Using the 2410 Refractometer

When you change solvents, be aware that:

• Changes involving two miscible solvents may be made directly. Changes involving two solvents that are not totally miscible (for example, from chloroform to water), require an intermediate solvent (such as isopropanol).

• Temperature affects solvent miscibility. If you are running a high-temperature application, consider the effect of the higher temperature on solvent solubility.

• Buffers dissolved in water may precipitate when mixed with organic solvents.

When you switch from a strong buffer to an org anic solv ent, ﬂush the buffer out of the system with distilled water before you add the organic solvent.

To change solvents:

1. Make sure the 2410 refractometer Purge Out line goes to waste.

2. To prevent backpressure in the column, replace the column with a union.

3. Set the pump or solvent delivery system ﬂow rate to 5 mL/min.

4. Press 2nd Func, then Purge.

5. Let the 2410 refractometer purge for a minimum of 5 minutes.

6. Press 2nd Func, then Purge to stop purging.

7. Follow steps 1 through 5 to purge the 2410 refractometer with 10 percent methanol-water before storing it.

5.4 Shutting Down the 2410 Refractometer

Note: Do not power off the 2410 refractometer unless you are storing it.

If you are not storing the 2410 refractometer, set the ﬂow rate to 0.1 mL/min and keep the pump or solvent delivery system operating. This minimizes the amount of time the 2410 refractometer needs for reequilibration when you use it again.

Do not leave buffers in the system after use. Flush the lines ﬁrst with HPLC-grade water and then with a suitable solvent (Waters recommends HPLC-grade methanol).

STOP

Attention If your storage solvent is incompatible with your column, remove the column

before ﬂushing.

Power off peripheral devices before shutting down the 2410 refractometer. To power off the 2410 refractometer, press the ON/OFF switch located at the lower right front corner of the unit.

Shutting Down the 2410 Refractometer 5-15

5-16 Using the 2410 Refractometer

Waters 2410 Operator's Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

Table of Contents

How to Use This Guide

Waters 2410 Theory of Operation

1.1 Overview

1.2 Theory of Operation

1.2.1 Optical Refraction

1.2.2 Differential Refractometry

1.2.3 Common RI Detection Problems

1.3 Principles of Operation

1.3.1 Fluidics

1.3.2 Optics

1.3.3 Electronics

Installing the 2410 Refractometer

2.1 Introduction

2.2 Site Selection and Power Requirements

2.3 Unpacking and Inspection

2.4 Making Electrical Power Connections

2.5 Making Fluidic Connections

2.5.1 Connecting a Column or Second Detector

2.5.2 Connecting to Waste

2.5.3 Connecting to a Drip Tray

Making Signal Connections

3.1 Component Connection Overview

3.2 Making IEEE-488 Signal Connections

3.2.1 Connecting to a Waters Data System Using the IEEE-488 Bus

3.2.2 Connecting to a Waters PowerLine System Controller

3.3 Making Non-IEEE-488 Signal Connections

3.3.1 Connecting to a Stand-Alone 2690 Separations Module

3.3.2 Connecting to the Waters 745/745B/746 Data Module

3.3.3 Connecting to a Chart Recorder

3.3.4 Connecting to the Waters 845/860 ExpertEase System

3.3.5 Connecting Injection Trigger Signals

3.3.6 Polarity Connections

3.4 Connecting the External Column Heaters

Preparing Solvents

4.1 Common Solvent Problems

4.2 Selecting a Solvent

4.3 Solvent Degassing

4.3.1 Gas Solubility

4.3.2 Solvent Degassing Methods

4.3.3 Solvent Degassing Considerations

Using the 2410 Refractometer

5.1 Using the Front Panel

5.1.1 Keypad Functions

5.2 Selecting Parameter Values

5.2.1 Sensitivity Guidelines

5.2.2 Scale Factor Guidelines

5.2.3 Time Constant Guidelines

5.2.4 Temperature Guidelines (Ext1 °C, Ext2 °C, Int °C)

5.2.5 Polarity Guidelines

5.3 Starting Up the 2410 Refractometer

5.4 Shutting Down the 2410 Refractometer