Refrigerated Cooling System - TKE

RCS-1TA INSTRUMENTS RCS ADDENDUM

109 Lukens Drive New Castle, DE 19720

Refrigerated CoolingSystem

Manual Addendum

For use with the following:DSC 10, 910, 912, 2010, 2910 and

2920 single & dual sample cells

PN 991103.002 Rev. J (Text Only)Issued November 2000

Thermal Analysis & Rheology

A SUBSIDIARY OF WATERS CORPORATION

RCS-2

Refrigerated Cooling System

TA INSTRUMENTS RCS ADDENDUM

© 1994, 1995, 1996, 1997, 1998, 1999, 2000TA Instruments, Inc.109 Lukens DriveNew Castle, DE 19720

Notice

The material contained in this manual is believedadequate for the intended use of this instrument.If the instrument or procedures are used forpurposes other than those specified herein,confirmation of their suitability must be obtainedfrom TA Instruments. Otherwise, TA Instru-ments does not guarantee any results andassumes no obligation or liability. This publica-tion is not a license to operate under or a recom-mendation to infringe upon any process patents.


Addendum:Refrigerated Cooling System

Safety .................................................... RCS-5Water Condensation ....................... RCS-5Cold Surfaces ................................. RCS-5Temperature Range ........................ RCS-6Declaration of Conformity .............. RCS-7

Introducing the RCS .............................. RCS-8Description ..................................... RCS-8Specifications ................................ RCS-10

Preparing the DSC .............................. RCS-12

Installing the RCS ............................... RCS-14Connecting Cables and Lines ....... RCS-21Using the RCS-DSC CellWithout the RCS .......................... RCS-25

LNCA .................................... RCS-25DSC Cooling Can ................... RCS-26Above Ambient Only.............. RCS-26

Using the RCS .................................... RCS-28Start-Up Time............................... RCS-28Setting the Flow Rates ................. RCS-28Setting Up an RCS Experiment .... RCS-30

Guidelines to PreventCondensation .......................... RCS-30Experimental Procedure ......... RCS-31

Controlling the RCS Usingthe Event Feature ......................... RCS-32

Changing the EventDefault Setting ........................ RCS-33

RCS-4



Example RCS Experiments .......... RCS-35DSC Heating Method ............. RCS-35DSC Cooling Method ............. RCS-36DSC Method toDry the RCS........................... RCS-37MDSCTM Method ................... RCS-37

Troubleshooting Guide......................... RCS-38

Parts List ............................................. RCS-44

Service and Ordering Information....... RCS-45


SafetyDue to the size and weight of the coolingaccessory, the RCS should always be lifted bytwo people to prevent injury.

The cooling head assembly contains coatedfiberfrax material. Excessive handling of thismaterial could cause fiberfrax particles to beemitted into the air. See the MSDS sheet forsafety measures to be observed when fiberfraxis used.

The RCS contains hazardous materials (i.e.,flammable refrigerants). Contact TA Instru-ments prior to packaging for shipment.

Water Condensation

The DSC and RCS surfaces get cold during useof the RCS. The cold surfaces can causecondensation and, in some cases, frost to buildup. This condensation may drip to the floor.Provisions to keep the floor dry should be made.A slipping hazard may result if the condensationis not cleaned up.

Cold Surfaces

Some surfaces of the RCS and DSC system mayget extremely cold during the use of the RCS forcooling experiments. This presents a danger toexposed skin coming in contact with and adher-ing to the cold surfaces. Use forceps or gloveswhen handling the lids, etc. while the RCS isbeing used.

Safety

NOTE:

t CAUTION:

t CAUTION:

t CAUTION:

RCS-6



Temperature Range

Do not exceed 400°C with the RCS coolinghead installed and the RCS power off. Seriousdamage and/or injury could occur.

Do not exceed 400°C with the RCS systeminstalled. If you wish to heat above 400°C, youmust first remove the RCS cooling head andgaskets from the RCS-DSC cell, then replace thethermal radiation shield, cell cover, silver lid,and bell jar. Even after these steps have beentaken, do not exceed 600°C with the RCS-DSCcell. Follow the directions in this manual forRCS usage.

t CAUTION:

!WARNING


Declaration of Conformity

In order to comply with the ElectromagneticCompatibility standards of the European CouncilDirective 89/336/EEC (EMC Directive) andDirective 73/23/EEC on safety, as amended by93/68/EEC, the following specifications apply tothe TA Instruments 230-Volt RefrigeratedCooling System:

� EN 55022, 1995 Limits and methods ofmeasurement of radio disturbancecharacteristics of Information TechnologyEquipment, class B.

� EN 50082-1, 1992 ElectromagneticCompatibility - Generic immunity standard -Part 1: Residential, commercial, and lightindustry

� IEC 801-2 Electrostatic Discharge 8 kVdirect air discharge

and indirect discharge� IEC 801-3 Radiated, radio frequency,

electromagnetic fieldimmunity test

� IEC 801-4 Fast Transients commonmodel 1 kV

� EN 61010-1, 1993 Safety requirements forelectrical equipment for measurement,control and laboratory use, and Amendment2, 1995.

RCS-8



Introducing the RCS

Description

The Refrigerated Cooling System (RCS) consistsof a two-stage, cascade, vapor compressionrefrigeration system with an attached coolinghead. The cooling head fits over the RCS-DSCcell for use with the DSC 10, 910, 912, 2010,2910 and 2920 single and dual sample cells.

Figure RCS.1Refrigerated Cooling System

The RCS can be used for experiments requiringcooling within an operating range of -70°C to400°C. The maximum rate of cooling dependson the temperature range of your experiment.(See the �Specifications� section for maximumcooling rates.)


The housing of the cooling head is heated toprevent condensation and frost build-up on theexterior of the head. Purge gases are supplied tothe cooling head from the refrigeration cabinet.The rear panel of the RCS cabinet has twoseparate gas connection ports: one for nitrogen(used with most experiments) and one for helium(used to enhance cooling performance forquicker cooling, but will hinder the cell�s ability toachieve higher temperatures [> 250�300°C], dueto its efficiency as a heat transfer medium.)You can choose between two purge gases byprogramming the switching of the gas supply viathe Gas segment in your method. The coolinghead purge gas acts as a heat transfer mediumbetween the DSC cell and the heat exchanger inthe cooling head and also reduces moistureaccumulation in the cooling head.

The RCS has two modes of operation, which areselected by using a switch on the front panel. Inthe MANUAL mode, the RCS runs continu-ously. When you select the EVENT mode, theRCS can be turned on by Event/On selectedfrom the Control menu in the DSC instrumentcontrol window. The RCS can be turned off bythe Event segment in a method, by the method-end conditions selected, or by the DSCAutosampler sequence settings.

Rapid on/off cycling of the RCS will damage therefrigerant compressors.

To achieve the highest cooling rate, use heliumgas to purge the cooling head. Once the RCS isinstalled on your DSC cell, you can easily accessyour samples by removing the lids from thecooling head housing and the heat exchanger,exposing the lid of the DSC cell.

Introducing the RCS

t CAUTION:

RCS-10



Specifications

Table RCS.1Cooling Rate Specifications

Cooling Rate Minimum Temperature

20°C/min 25°C

10°C/min -25°C

5°C/min -50°C

Cooling rates are obtained using 150 ml/min helium cooling head purge and 25 ml/min nitrogen DSC cell purge.

Cooling rate will usually be improved byincreasing the helium flow or by usinghelium instead of nitrogen for the cellpurge.


Introducing the RCS

Table RCS.2Accessory Specifications

Only values with tolerances or limits guaranteeddata. Values without tolerances are for informa-tion only.

DimensionsWidth 10 in. (25.4 cm)Depth 20 in. (50.8 cm)Height 18.5 in. (47 cm)

Weight 70 lbs (32 kg)

TemperatureRange -70°C to 400°C

Voltage 120 V 230 VCurrent 7 A 5 APower on VA 840 VA 1100VA

Fuse Types 120-volt 230-voltRCS RCS

250 V, 250 V,3/4 amp 1/2 amp

Fast acting Fast actingglass glass

Refrigerants Ethane, propane, propylene

RCS-12



Preparing the DSCIn order to allow the RCS cooling head to mountcorrectly to the DSC cell and obtain the bestcooling performance, a specialized DSC cellmust be used with the RCS. This cell includes aflanged metal sleeve as seen in the illustrationbelow.

If you have the original DSC cell currentlyinstalled on your instrument, you will need toprepare your instrument for RCS use by follow-ing the steps in this section to mount the RCS-DSC cell.

Figure RCS.2Specialized RCS-DSC Cells

Allow the DSC to cool to ambient temperaturebefore attempting to perform the stepsbelow.

RCS Flange RCS-DSC Cell usedfor DSC 10, 910, 912,and 2910. This issimilar to the built-incell used with the DSC2010.

RCS-DSC Cell usedfor DSC 2920

t CAUTION:


1. Remove the bell jar, cell cover, and silver lidfrom the DSC cell currently installed on yourinstrument. Then remove the original cellfrom the instrument.

2. Remove the RCS-DSC cell from its shippingcontainer.

3. Remove the three (3) screws that secure theradiation shield to the RCS-DSC cell assem-bly and remove the radiation shield, refer toFigure RCS.3.

Figure RCS.3Parts of the DSC Cell

4. Mount the RCS-DSC cell on your instrumentas you would mount the original DSC cell.Refer to your DSC Operator�s Manual forinstructions, if needed.

You are now ready to install the RCS assembly.

RETAININGSCREWS

METALSLEEVE

THERMALRADIATIONSHIELD

Preparing the DSC

RCS-14



Installing the RCSWhen you receive the RCS, place it near theDSC instrument, leaving at least 10 cm (fourinches) clearance on all sides of the refrigerationcabinet for air flow.

1. Install the large rubber gaskets over theRCS-DSC cell as required for your instru-ment type: three 3.2 mm (1/8-inch) thickgaskets are required for 2010 and 2920instruments, and one (1) gasket is requiredfor all other DSC instruments. An extragasket, measuring 1.6 mm (1/16-inch) thick,is also supplied in your RCS kit. This is anoptional gasket that can be used as neededto seat the cooling head properly over thecell as described in step 3.

2. Orient the refrigeration cabinet so that therefrigerant line forms a loose loop and thecooling head slides easily over the cellwithout twisting the refrigerant line.

Do not twist the refrigerant line so that thecooling head is forced down onto the cell.Readjust the position or the orientation of therefrigerant cabinet so that the cooling headslides easily over the cell.

3. Install the cooling head, after the gasketshave been installed, as follows:

a. Press down lightly on the cooling headand observe the gap between the bottomof the cooling head baseplate and the topof the gasket stack. If this gap is

t CAUTION:


approximately 1.0 mm (0.04 inch),continue the installation with step 3b. Ifthe gap is appreciably less, lift thecooling head off the cell and replace the3.2 mm (1/8-inch) top gasket with thesupplied 1.6 mm (1/16-inch) gasket.Slide the RCS cooling head over the celland continue with step 3b.

b. Press down on the cooling head assem-bly and look down into the top of thecooling head assembly to make sure thatthe inside diameter of the heat ex-changer (the copper colored ring) isconcentric with the inside diameter ofthe top of the RCS-DSC cell. If it is not,repeat steps 1 and 2.

4. Look inside the top of the cooling headassembly again after you have made surethat it meets the criteria in step 3b. Thereshould be a small uniform gap (~1.0 mm[~0.040 inch]) between the underside of thecopper heat exchanger and the top of thecell and between the bottom of the anti-frostsleeve and the top of the copper heatexchanger. If the gaps are too large, repeatsteps 1, 2, and 3. See the arrows on FigureRCS.4, on the next page, for the location ofthe gaps.

Installing the RCS

RCS-16



Figure RCS.4Relationship of DSC Cell toCopper Heat Exchanger

5. Locate the screws (included in the RCSAccessory Kit) that are needed for yourtype of DSC instrument. Refer to FigureRCS.5 to decide which screws you willneed.

Gaps ~ 1.0 mm (0.040 inch)

Anti-frostSleeve

CopperHeatExchanger

DSC Cell


Figure RCS.5Screws

6. While pressing down on the cooling headassembly, install two (2) screws through thebaseplate of the cooling head assembly.

� DSC 2920 and 2910: Tighten thethumbscrews evenly until they are hand-tight.

� DSC 10, 910, 912, 2010: Tighten thescrews using a hex key until they arejust snug.

The baseplate of the cooling head should betight against the gasket(s) on the DSC cell.If it is not, check to be sure the rubbergaskets are installed correctly over the DSCcell as described in step 1 and repeat steps 3and 4.

See Figures RCS.6, 7 and 8 for correctinstallation of the RCS Assembly on theDSC 2010, 2910 and 2920.

DSC 2920DSC 2010DSC 10, 910,

912, 2910

Original DSC 10, 910,912, 2910 thumbscrews(Not used with the RCS)

Installing the RCS

RCS-18



7. Look down into the top of the cooling headassembly to make sure that the insidediameter of the heat exchanger (the coppercolored ring) is concentric with the insidediameter of the top of the DSC cell. Thereshould be a small uniform gap (~1.0 mm[0.040 inch]) between the underside of thecopper heat exchanger and the top of theDSC cell. If proper alignment is not obtained,remove the thumbscrews and repeat steps 3through 7.

8. Set the module mode on the controller toaccommodate the use of mechanical cooling:

Choose the RCS mode, then you canproceed with the rest of the installation.

To run MDSCTM experiments with the DSC2910, you must use the mode “DSC Modu-lated.” Be careful not to exceed 400°C in thismode.

9. Place a cap over the vacuum and air coolports on all DSC instruments to preventmoisture from entering through those ports.

� DSC 2010, 2910, and 2920: Do notuse compressed air for cooling when youare using the RCS. Most compressedair has a high moisture content and thiswill cause water and ice to condensearound the cell. Laboratory quality dryair may be used for this purpose.

NOTE:


Installing the RCS

Figure RCS.6RCS Mounted on the DSC 2010


RCS-20





ConnectingCables and Lines

The DSC Module Accessory Kit contains thecables that you will need to install before theRCS can be operated. Obtain the cables fromthe kit and follow these instructions to installthem.

1. Turn the RCS cabinet around so that youcan easily see the back panel. Locate theconnections shown in Figure RCS.9.

Figure RCS.9RCS CabinetBack Panel

Power cableconnection

Fuse Holder(s):1 holder for115V/60Hz2 holders for220V/50 Hz

GAS 1 N

2

GAS 2 He

EventCableConnections

Installing the RCS

Gas CableConnections

RCS-22



2. Each purge gas should have a flowmeterinstalled in the supply line to the RCScabinet. Connect the nitrogen and heliumsupply sources (gas lines not supplied) to theappropriate connections on the rear panel ofthe RCS cabinet (see Figure RCS.11).*The recommended flow range is 0�150 ml/min.

* Make sure that the gas line connections are leakfree, as leaks will reduce the purge gas flow, witha resulting loss in cooling performance.

Recommendations:

� Heating: Nitrogen at GAS 1.

If you are only using one gas, it is recommendedthat it be connected to GAS 1.

� The cooling head purge gas is used to keepa dry environment and to mediate heatexchange between the cooling head and theDSC cell. It does not eliminate the need toalso use a purge gas for the DSC cell.

� The gas connection labeled GAS 1/N2 isnormally open and should be connected tothe gas that is used the most. This gas willflow when the Gas method segment is in the1 state or the RCS is turned off.

� The gas line connected to the connectionlabeled GAS 2/He will flow when the Gassegment is switched to state 2, and the RCSis turned on.

NOTE:


� Cooling: Helium at GAS 2. Formaximum cooling performance, helium mustbe used for one of the cooling head purgegases. Please note that the maximumtemperature that can be achieved, whenusing helium as the cooling head purge, isapproximately 200°C. You can conservehelium by using nitrogen for the cooling headpurge gas during the heating portion of themethod or when cooling requirements arenot so great.

3. Locate the gas cable in the DSC ModuleAccessory Kit.

4. Connect the gas cable to the terminals on therear of the RCS cabinet and the other end tothe DSC or Module Interface using theappropriate connector (see Figure RCS.10on the next page).

5. Check that the power switch is turned off,then plug in the power cable�first to theRCS cabinet, then to the outlet.

Installing the RCS

RCS-24



Figure RCS.10Rear Panel of RCSCabinet with Connections

RedConnectors

BlackConnectors

Gas Cable

GasLines

Power Cable

Event Cable


Using the RCS-DSCCell Without the RCS

Once the RCS-DSC cell is installed on theinstrument you can perform experiments usingthe Refrigerated Cooling System, as well asother types of experiments. However, there aresome experiments that will require you to placeyour original DSC cell on the instrument.

LNCA

Please note that the LNCA can only be used ifyou modify the RCS-DSC cell. This is becausethe LNCA heat exchanger will interfere with theflanged metal sleeve.

� If you can remove the RCS-DSC cell fromyour instrument, it is best to take it off andplace your original DSC cell back on theinstrument to run the LNCA.

� If your cell is permanently attached, such asthe DSC 2010, you will need to modify theRCS-DSC cell with insulation tape. Referto the DSC 2010 Operator�s Manual fordirections, or the installation instructionsheet that comes with the insulation tape kit.

Once you have installed the insulation tape on theRCS-DSC cell to use it with the LNCA, this becomesa permanent change. The cell cannot bereconfigured as a standard RCS-DSC cell.

Installing the RCS

NOTE:

RCS-26



DSC Cooling Can

The DSC Cooling Can may be used with theRCS-DSC cell, if you place the aluminumspacer (supplied with the RCS Accessory Kit)on top of the DSC cell before installing thecooling can.

Above Ambient Only(No Cooling Required)

RCS-DSC cells may be used for above ambientexperiments that do not require the RCS:

� Temperatures from ambient to 400°C: TheRCS-DSC cell may be used with the RCScooling head in place and the RCS turnedoff. It is preferable, however, that the RCShead be removed prior to running aboveambient experiments.

� Temperatures above 400°C: You mustremove the RCS cooling head and gasketsfrom the cell. Then place the thermalradiation shield, cell cover, silver lid, andbell jar back on the cell before runningexperiments above 400°C.

The RCS-DSC cell may only be used up to 600°C.

Do not exceed 400°C with the RCS coolinghead installed and the RCS power off. Seriousdamage and/or injury could occur.

NOTE:

!WARNING


Do not exceed 400°C with the RCS systeminstalled. If you wish to heat above 400°C, youmust first remove the RCS cooling head andgaskets from the RCS-DSC cell, then replace thethermal radiation shield, cell cover, silver lid, andbell jar. Even after these steps have been taken,do not exceed 600°C with the RCS-DSC cell.Follow the directions in this manual for RCSusage.

Using the RCS

t CAUTION:

RCS-28



Using the RCSWhen in use the RCS runs continuously, at afairly constant temperature, creating a lowtemperature heat sink surrounding the RCS-DSCcell. Heat flows from the cell to the heat sink,cooling the cell. There is no control over thetemperature of the RCS.

Start-Up Time

The RCS will not begin to cool the RCS-DSCcell until the second stage compressor begins torun, this is indicated by the green light on thefront panel of the refrigeration cabinet. Whenstarting from room temperature, it will normallytake approximately 15 to 20 minutes for theRCS to reach operating temperature after thegreen light goes on. Purge gas must be flowingthrough the DSC cell and the RCS cooling headduring initial cool down to prevent condensationand subsequent frost build-up.

To operate the RCS, first set the gas flow ratesas explained in the next section.

Setting theFlow Rates

1. Set the flow rate of the DSC cell purge to 25ml/min.

When using the RCS with the DSC 2920 Autosam-pler, the recommended DSC cell purge rates are25 ml/min for nitrogen and 25 ml/min for helium.

NOTE:


2. Turn on the power switch on front of theRCS cabinet.

3. Set the flow rates of the RCS purge gases asfollows:

a. Set the flow rate for GAS 1 (usuallynitrogen connected to gas connectionGAS 1/N2), using the flowmeter, to 150ml/min.

b. Switch to Gas 2 using Control/Gas/2from the Instrument Control menu.

c. Set the flow rate for GAS 2 (usuallyhelium connected to gas connectionGAS 2/He), using the flowmeter, to 150ml/min.

For maximum cooling rates, helium should be usedas the GAS 2 purge gas.

Using the RCS

NOTE:

RCS-30



Setting Up anRCS Experiment

General Guidelines toPrevent Condensation

You can load samples into the DSC cell whilethe RCS is running. To prevent condensation inthe DSC cell during sample loading, warm theDSC cell to a temperature above ambient usingone of the following procedures.

� Start your thermal methods with an Initialtemperature segment of 20�30°C. When theDSC cell is ready, as indicated by theREADY message on the controller screen,load the sample and select Resume to moveto the next method segment.

or

� Keep the DSC cell warm by inserting theInitial temperature method segment at theend of the previous thermal method. To startthe new experiment, first select STOP, thenSTART.

Loading samples when the DSC cell is belowambient temperature will almost always causecondensation within the DSC cell, resulting inerroneous heat flow data.

NOTE:


Experimental Procedure

1. Remove the RCS outer lid, middle lid andthe DSC cell silver lid.

2. Load your sample and reference pans, thenreplace the lids.

3. Set up the thermal method with the follow-ing guidelines (see example experiments onpages RCS-35 to 38):

� During cooling segments, use helium topurge the RCS cooling head.

� During heating segments, use nitrogento purge the RCS cooling head.

� Use the Gas segment to switch betweennitrogen and helium during a thermalmethod. Switch the gas at the beginningof a heating or cooling method segment.

� Use an Initial temperature segment atthe end of each method to set the celltemperature to room temperature andminimize condensation while removingthe sample and loading the next sample.(Note: Be sure to end the currentexperiment by pressing STOP, then youcan begin the next experiment.)

When using the RCS with the DSC 2920 Autosam-pler, air cool can be activated automatically at theend of the run to quicken the cell’s return toambient temperature. It is recommended that youuse only laboratory quality dry air for this purposeto minimize moisture and frost condensationaround the cell and prevent contamination of thecell by particulates and oil found in the compressedair.

4. Start the experiment.

Using the RCS

NOTE:

RCS-32



Controlling the RCSUsing the Event Feature

The RCS can be controlled using one of the twoswitches found on the front panel�theMANUAL switch or the EVENT switch.

� When the switch on the front panel of theRCS is set to MANUAL, the RCS willoperate in the standard mode and willremain ON at the end of a method.

� When the switch on the front panel of theRCS is set to EVENT, the instrument willuse the event feature of the DSC.

To use the event feature follow the instructionsfound in this section.

1. Make sure that the RCS purge gas is flow-ing, then turn on the RCS power.

2. Turn the toggle switch on the front of theRCS panel to EVENT.

This allows the RCS to be turned on whenEvent On is selected from instrumentcontrol program on the controller and to beturned off the RCS when Event Off isselected. The default setting for the Eventfunction is to be automatically turned off atthe end of a method. This feature will letyou set up a long experiment to rununattended and the RCS will shut downautomatically at the end of the experiment.


The default setting for the Event feature cannot bechanged when using the RMX or OS/2 instrumentcontrol software. If you want the RCS to remain onat the end of a run, you must set the toggle switchon the front panel of the RCS to MANUAL.

3. Select Control/Event/On from the instru-ment control program.

4. Allow 15 to 20 minutes for the temperatureof the RCS to stabilize before you begin anyexperiments.

We do not recommend that you turn the RCS onand off rapidly after short experiments.

Changing theEvent Default Setting

When using the TA Instruments ThermalSolutions/Advantage software, you can changethe default setting for the event feature for theDSC or the DSC Autosampler using one of thefollowing procedures.

Event Control with the DSC

To control the event feature when you are usingthe DSC, follow these steps:

1. Switch the RCS to the EVENT mode.

2. Select the Instrument Parameters window(TS) or the Post Test window (Advantage)for the DSC instrument.

3. Check Event (RCS) Unchanged box in theMethod-End Conditions.

Using the RCS

NOTE:

t CAUTION:

RCS-34



When you perform these steps, the RCS willremain on at the end of an experiment. Thisallows you to perform a series of experimentsand the RCS remains on at the end of eachmethod. For the last experiment, the RCS canbe turned off automatically at the end of themethod by including an Event Off segment inthe method or by unchecking the Event (RCS)Unchanged box before you start the last experi-ment. This procedure typically applies whenyou are not using the DSC Autosampler.

Event Control with the DSC Auto-sampler

To control the event feature when you are usingthe DSC Autosampler, follow these steps:

1. Switch the RCS to the EVENT mode.

2. Select the Instrument Parameters window(TS) or the Post Test window (Advantage)for the DSC Autosampler instrument.

3. Check the Event (RCS) Unchanged box inthe Method-End Conditions so that the RCSwill remain on after each method in thesequence.

4. For Thermal Solutions: Select Autosam-pler/Settings from the AutoDSC menu.Select the Stop Page, then check the Event(RCS) Off box, which controls the condi-tion of the RCS at the end of the sequence.

For Thermal Advantage: Select UserPreferences � Auto Sampler Page fromthe AutoDSC menu. Check the Event(RCS) Off box, which controls the condi-tion of the RCS at the end of the sequence.


Checking this box turns off the RCS com-pressor at the end of the Autosamplersequence. If Event (RCS) Off is notselected, then the RCS compressor remainson at the end of the sequence.

When you perform these steps, the RCS willremain on at the end of each method in thesequence in order to be used for the nextmethod, but will turn off at the end of theAutosampler sequence. This allows you to runautosampler cooling methods using the RCSunattended and it will not continue to run whennot needed.

Example RCS Experiments

DSC Heating Method

Method Segments Purpose

1 Data Storage: OFF Turns data collection off2 Initial temperature*: 30.00°C Nitrogen is default cooling head

purge gasMinimizes condensation whileloading the sample

3 Select Gas: 2 Switch to helium for rapid cooling4 Ramp 10°C/min to -50°C Cool to start temperature5 Isothermal for 5 min Temperature stabilization6 Select Gas: 1 Switch to nitrogen for heating7 Data Storage: ON Turns data collection on8 Ramp 10°C/min to 300.00°C Heating ramp9 Data Storage: OFF Turns data collection off10 Initial temperature: 30.00°C Minimizes condensation while

removing the sample or loading thenext sample.

Using the RCS

(continued on next page)

RCS-36



DSC Cooling Method


1 Data Storage: OFF Turns data collection off2 Initial temperature*: 30.00°C Nitrogen is default cooling head

purge gasMinimizes condensation whileloading the sample

3 Ramp 25°C/min to 300°C Heating ramp4 Isothermal for 5 min Temperature stabilization5 Select Gas: 2 Switch to helium for rapid cooling6 Data Storage: ON Turns data collection on7 Ramp 10°C/min to -25.00°C Cooling ramp8 Data Storage: OFF Turns data collection off9 Select Gas: 2 Switch to nitrogen for heating10 Initial temperature: 30.00°C Minimizes condensation while

removing the sample or loading thenext sample.

* When using the Initial temperature segment atthe beginning of an experiment, it is necessary forthe operator to select RESUME under InstrumentControl in order to go to the next segment in themethod.

NOTE:


DSC Method to Dry the RCS

To dry the RCS cooling head assembly, first turn offthe RCS.


1 Data Storage: OFF Turns data collection off2 Equilibrate at 200°C Nitrogen is default cooling head

purge gasEliminates any condensation

3 Isothermal for 60.00 min Brings heat exchanger totemperature

4 Initial temperature 30.00°C Brings cell to room temperature

MDSCTM Method


Nitrogen is default cooling headpurge gas

1 Data storage: Off Save disk space2 Initial temperature*: 30.00°C Minimizes condensation while

loading the sample3 Select Gas: 2 (See NOTE on Switch to helium for increased next page.) cooling efficiency4 Ramp 10°C/min to -50.00°C Cool to start temperature5 Modulate + 0.5°C for 60 sec Start modulation6 Isothermal for 5.00 min Modulation stabilizes7 Data storage: On Start data collection8 Ramp 5.00°C/min to 200.00°C Ramp during modulation9 Data storage: Off Stop data collection

10 Select Gas: 1 Switch to nitrogen11 Modulate + 0.000°C for 60 sec Turns off modulation12 Initial temperature: 30.00°C Minimizes condensation while

removing the sample

* See note about Initial temperature segment on page RCS-36.

NOTE:

Using the RCS

RCS-38



The maximum temperature that can be achieved,when using helium as the cooling head purge, isapproximately 200°C. Use nitrogen from thebeginning of the experiment, if it is necessary toexceed 200°C.

TroubleshootingGuide

The problems most often encountered whenusing the Refrigerated Cooling System areusually related to improper installation andsetup. This section lists the type of problem andpossible solutions to fix the situation.

Problem:

Poor baseline performance, including excessivenoise, extraneous thermal events, and poorreproducibility.

Solution:

Check the following items:

1. Make sure that an RCS-DSC cell (not astandard DSC cell) has been installed on theinstrument. The RCS cooling head can beinstalled on any DSC cell, but will not workdue to improper alignment with the standardDSC cell.

2. Check the alignment of the RCS coolinghead on the RCS-DSC cell to make sure thatit is properly installed as described in thisaddendum.

NOTE:


3. Make sure that the correct thumbscrews areinstalled and tightened, and that the base-plate of the RCS cooling head is tightagainst the rubber gaskets.

4. Make sure there is no accumulation of icewithin the cell or inside the cooling head.Purging the RCS-DSC cell and the RCShousing helps prevent the accumulation ofice. Follow these suggestions to correct thisproblem, if you suspect an ice accumulation:

a. Check to make sure that the cell purgegas is connected, and that the flow rateis correct. Also check to make sure thatthe cooling gases are connected to theRCS, there are no leaks in the lines, andthat the gas flows are correct.

b. Check to make sure that the vacuum andair cool ports on the cell base have caps.

c. If all of the gas connections and flowrates are found to be correct, the cell andRCS cooling head should be dried asfollows to eliminate moisture:

To dry the system, turn the RCS off, butmaintain the flow of purge gas to thecell and cooling gas to the RCS. (Notethat with the RCS turned off, the coolinggas connected to GAS 1 port willcontinue to flow.) Now execute athermal method which will hold the cellat 200°C for one hour (see exampledrying method).

Troubleshooting Guide

RCS-40



Problem:

Cooling rates are too low or cannot be main-tained to a low enough temperature.

Solution:


1. Make sure that the cooling gases are prop-erly connected to the RCS cabinet, and thatthe flow rates are correct.

2. Use a high thermal conductivity gas (e.g.,helium) as the cell purge gas to achievemaximum cooling rates:

a. Make sure that the high thermal conduc-tivity gas is connected to the GAS 2 porton the RCS cabinet.

b. Ensure that the thermal method includesa Gas 2 segment to switch to the highthermal conductivity gas before execut-ing cooling segments.

c. Try increasing the helium flow, this willusually improve your cooling rates.

3. Check the installation of the RCS coolinghead on the cell to make sure that the heatexchanger is properly aligned and has the1.0 mm (~0.40-inch gap).

4. Make sure that the correct thumbscrews areinstalled and tightened. Check the baseplateof the RCS cooling head to make sure it istight against the rubber gaskets.


5. Make sure that the vacuum and air coolports on the cell base have caps.

Problem:

Cooling light on the RCS does not illuminate.

Solution:

1. If you are beginning a thermal method withthe RCS-DSC cell at an elevated tempera-ture, the green cooling light on the frontpanel of the RCS cabinet may take longerthan usual to illuminate. It may go on andoff several times during cooling beforefinally remaining illuminated. This isnormal and does not indicate a fault. It isoccurring because the heat exchanger in theRCS cooling head is hot.

2. If the RCS is turned on while the RCS-DSCcell is being maintained at a high tempera-ture, the cooling light may continue to cycleor may not illuminate. Reduce the celltemperature before starting the RCS. TheRCS cannot start when running a thermalmethod that holds the cell at a high tempera-ture.

3. If none of the situations above is in effect,and the green cooling light fails to illumi-nate, it indicates fault with the refrigerationsystem and the RCS unit must be returnedfor service.


RCS-42



Problem:

Specified minimum temperature cannot bereached.

Solution:


1. Make sure that the cooling gases are prop-erly connected to the RCS cabinet, and thatthe flow rates are correct.

2. Use a high thermal conductivity gas (e.g.,helium) as the cell purge to achieve maxi-mum cooling rates:

a. Make sure that the gas is connected tothe GAS 2 port on the RCS cabinet.

b. Ensure that the thermal method includesan Gas 2 segment to switch to the highthermal conductivity gas before execut-ing cooling segments.

c. Try increasing the helium flow, this willusually improve your cooling perfor-mance.

3. Check the installation of the RCS coolinghead on the cell to make sure that the heatexchanger is properly aligned and has the1.0 mm (~0.40-inch gap).

4. Make sure that the correct thumbscrews areinstalled and tightened. Check the baseplateof the RCS cooling head to make sure it istight against the rubber gaskets.


5. Make sure all gas connections are free ofleaks.

6. Make sure that the vacuum and air coolports on the cell base have caps.

Problem:

Cannot achieve 400°C temperature.

Solution:

Make sure that nitrogen is being used by select-ing Gas 1 (Nitrogen). The maximum tempera-ture that can be achieved when using helium asthe cooling head purge is approximately 200°C.

Problem:

Cannot equilibrate at a temperature (low orhigh).

Solution:

Use a Ramp segment in your method instead ofthe Equilibrate segment.

Problem:

Condensation forms on the top of the coolinghead and/or on the inner stainless steel lid.

Solution:

Verify that a 1-mm (0.04-icnh) gas existsbetween the bottom of the anti-frost sleeve andthe top of the copper heat exchanger. See FigureRCS.4 on page 16.


RCS-44



Parts ListPart Number Description

990697.001 Cooling AccessoryGasket3.2 mm (0.12-inch) thick

990697.002 Cooling AccessoryGasket1.6 mm (0.06-inch) thick

991115.001 Middle Lid #2 (stainlesssteel)

990686.001 Outer Lid #3 (aluminum)990674.001 Sockethead Cap Screw

(Modified) - Bottom(DSC 10, 910, 912, 2910)

990674.002 Sockethead Cap Screw(Modified)(DSC 10, 910, 912, 2910)

205085.058 Sockethead Cap Screw(DSC 2010)

915033.901 Shoulder Thumbscrewwith Retainer Ring(DSC 2920)

270305.001 Hex Key 4.8 mm (3/16inch)

270406.001 Hex Key 4.0 mm (5/32inch)

991118.001 Cooling Can Spacer253827.000 Power Cord - 120 V/60

Hz270469.001 Power Cord - 230 V/50

Hz991123.001 Silver Lid #1 for RCS-

DSC Cell205225.020 Fuse, Fast Acting, Glass,

0.75 Amp/125 V(1 each required for 120V/60 Hz)

205225.018 Fuse, Fast Acting, Glass,0.50 Amp/250 V(2 each required for 230V/50 Hz)


Service andOrdering Information

Service and Ordering Information

TA Instruments, Inc.109 Lukens DriveNew Castle, DE 19720Telephone: 1-302-427-4000 or

1-302-427-4040Fax: 1-302-427-4001

HELPLINE�U.S.A.For assistance with thermal analysis applications,please call the Thermal Analysis Help Deskat 1-302-427-4070.

SERVICE�U.S.A.For instrument service and repairs,please call 1-302-427-4050.

TA Instruments Ltd.Europe House, Bilton CentreCleeve RoadLeatherhead, Surrey KT22 7UQEnglandTelephone: 0-11-44-1372-360363Fax: 0-11-44-1372-360135

TA Instruments GmbHMax-Planck-Strasse 11D-63755 AlzenauGermanyTelephone: 49-6023-9647-0Fax: 49-6023-9647-77

TA Instruments BelgiumA Division of Waters s.a./n.v.Raketstraat 60B-1130 BrusselsTelephone 32-2- 706 00 80Fax 32-2- 706 00 81

RCS-46



TA Instruments The NetherlandsA Division of Waters Chromatography B.V.Florijnstraat 194879 AH Etten-LeurTelephone 31-76- 508 72 70Fax 31-76- 508 72 80

TA Instruments JapanNo. 5 Koike Bldg.1-3-12 KitashinagawaShinagawa-Ku, Tokyo 140JapanTelephone: 813/3450-0981Fax: 813/3450-1322

TA Instruments FranceB.P. 60878056 Saint-Quentin-YvelinesCedex, FranceTelephone: 33-1-30-48 94 60Fax: 33-1-30-48 94 51

TA Instruments SpainWaters Cromatografía, S.A.División TA InstrumentsAvda. Europa, 21. Pta. Baja28108 AlcobendasMadrid, SpainTelephone: 34-91-661-8448Fax: 34-91-661-0855

TA Instruments AustraliaUnit 338-46 South StreetRydalmere NSW 2116AutstraliaTelephone: 61-29-9331-705Fax: 61-29-8981-455

TA Instruments ItalyDivision of Waters SpAvia Achille Grandi 2720090 Vimodrone (MI), ItalyTelephone: 39-02-27421-1Fax: 39-02-250-1827

Refrigerated Cooling System - TKE

Documents

Transcript of Refrigerated Cooling System - TKE