Selecting the Instrument PreferencesSelecting the Instrument Preferences
You can set up certain operating parameters for your instrument through the instrument control software by selecting Tools/Instrument Preferences. Several pages will be displayed to allow you to set these parameters. To display the desired page of Instrument Preferences, click on the corresponding tab.
Choose the topic below for more detailed information:
MFC Purge Page - Specifying the Connected Purge Gases
LCD Signals Page - Setting Up Signal Display Touch Screen
Touch Screen Page - Setting Up the Instrument Touch Screen
DSC Page - Setting Up DSC Options
Cooler Page - Selecting and Setting Up the Cooling Accessories
DSC Autosampler Page - Selecting DSC Autosampler Options
To set up the gases select Tools/Instrument Preferences, then click on the MFC Purge page. The appearance of this page differs slightly depending upon whether your instrument is equipped with mass flow controllers (MFC) or not.
Use Gas #1/#2 to specify the purge gases that are connected to the corresponding ports on the instrument. A purge gas is a gas, often an inert gas such as nitrogen, that flows through the instrument during the experiment.
Without MFC: If there are no mass flow controllers installed, Gas #1 and Gas #2 are routed directly from their respective ports to the cell and the flow must be regulated by a flow meter.
With MFC: If there is a mass flow controllers installed, Gas #1 and Gas #2 are routed directly from their respective ports to the cell and is flow regulated from the instrument control software
In addition, you can check the Stop experiment when flow rate deviates from the set value checkbox, if you would like to have the experiment stop in the event the flow rate cannot be maintained during an experiment (e.g., if the purge gas tank becomes empty).
If you are using a purge gas that is not one of the available options, you can select "outside purge," which fully opens the MFC valve requiring that the flow rate be controlled using an external flow meter. Or you can select a purge gas type from the drop-down list that has similar characteristics to the one you want to use (e.g., conductivity) and use that calibration table for controlling the flow rate via the MFC.
Select the flow rate of the purge gases on the Notes Page.
NOTE: If you are using laboratory purge gas, rather than bottle purge gas, you will need to install an external drier.
CAUTION: Use of corrosive gases will shorten the life of the instrument. NEVER use a corrosive gas.
WARNING: Use of an explosive gas as a purge gas is dangerous and is not recommended for this instrument.
You can set up and calibrate the touch screen by selecting Tools/Instrument Preferences, then clicking on the Touch Screen page to perform the following steps:
Select the desired Screen Saver Selection from the drop-down list. If you select "Custom," enter the desired Text using 20 characters or less.
Enter the desired Delay time in seconds.
NOTE: The screen saver will turn off automatically after one hour. Simply touch the screen to activate it again.
Calibrate the touch screen, if desired, by checking the Start Instrument Touch Screen Calibration box and click OK. A series of prompts will be displayed. To continue with the calibration, follow the directions displayed. Reset the instrument as directed and follow the prompts using a non-sharp, pointed object (such as a blunt pencil or pen) to tap the touch screen at the indicated points.
Click the OK button when finished.
To determine which signals coming from the instrument will be displayed on the Signal Display touch screen (touch the Display Menu key to display), select them from the dialog that is opened through the Tools/Instrument Preferences/LCD Signals page.
Select up to six signals. These signals will appear on the instrument touch screen.
NOTE: This does not affect the signals displayed on the instrument control Signal Display Pane. Those signals are customized using another function.
Select Tools/Instrument Preference/DSC page to open a dialog that allows you to select certain parameters that will be used by the instrument while it performs experiments.
Choose the topic below for more detailed information:
Choose the radio button that will set the way the data is plotted–either with the Transition Exotherm Up or Exotherm Down, depending upon your own personal preference. See the figures below for examples.
Choose the desired heat flow signal from the Heat Flow Selection drop-down list. For the most accurate results, the selected heat flow signal should be the same as that used for calibration. Changes to this option will require you to recalibrate for cell constant and temperature using the newly selected heat flow signal. If you do not recalibrate as directed, the heat flow results will be incorrectly calibrated.
Enter the desired temperature value that will be used when Control/Go to Standby Temp is chosen. This option is used when the selected cooler is LNCS or RCS and the Post Test temperature window is not used or stopped.
Click on the PCA Operation checkbox when you are operating a Photocalorimeter Accessory (PCA) with the DSC instrument. This is very important for proper operation of the instrument. When this checkbox is checked, the AutoLid and Autosampler are disabled and the Event state will always turn off after a method regardless of the RCS setting between runs (see below). If the PCA is checked and the cooler type is RCS, the RCS must be set to "Manual" (rather than "Event") on the back of the RCS instrument.
Select Single or Dual operation from the drop-down list. See About the PCA for more information.
The Enable Diagnostic Signals checkbox is only used for troubleshooting by your TA Instruments service representative. This is a diagnostic tool and should not be used unless directed to do so by a TA Instruments service representative.
Select Tools/Instrument Preference/Cooler page to open a dialog that allows you to select certain parameters that relate to the DSC cooling accessories and their use.
Choose the topic below for more detailed information:
Choose the type of cooling device that is to be used with your DSC from the Cooler Selection drop-down list (see Introducing the DSC Cooling Accessories for more information on the coolers). (The RCS40 is compatible with the DSC Q2000, Q200, and Q20 only.)
NOTE: When using the FACS quench cooler make sure that the Cooler Selection identified is the FACS and not the quench cooler. If the wrong cooler is identified your results will be inaccurate.
When using the RCS or LNCS, it is recommended that a source of dry nitrogen gas be connected to the cooling gas port if the instrument is used in high humidity environments or when recovering from moisture contamination. When the Activate secondary purge when lid is opened checkbox is used, the secondary purge will supply additional dry gas into the RCS and LNCS housing when the AutoLid is opened or when the PCA Operation box is checked.
This option should be left blank when there is not a secondary gas connected to the cooling gas port and/or the port is capped. See also: Connecting the Cooling Gas Line.
These items will be applied between runs, if selected.
Check the Leave RCS on option to leave the RCS on between runs. (Default = checked) See also: PCA Operation above.
Check the Leave LNCS on option to leave the LNCS between runs. (Default = checked)
Check the LNCS Autofill if below option, then enter a percentage to automatically fill the LNCS, if desired. This indicates that you want the LNCS to automatically fill at the end of an experiment when the level of liquid nitrogen falls below the specified percent. The fill process, when activated, will fill to completion before advancing to the next scheduled run. If left unchecked, you will need to manually fill the LNCS when needed. (Default = checked, 40%)
Use the Tools/Instrument Preferences/Autosampler page to set up the actions of the DSC Autosampler. The stop options instruct the Autosampler on the action to take when the run sequence has been stopped or runs to completion. The error handling options determine whether the Autosampler will keep going or halt when a nonfatal error is encountered.
These options will override the Post-Test conditions for the last run in the sequence. Select the desired stop sequence option (click for a definition):
NOTE: Autosampler sequence stop options are invoked even for a one run sequence when the Autosampler is enabled.
Check Unload pans, if you want the Autosampler to automatically unload the pans from the cell and place them either in the sample tray or the waste bin. If this is left unchecked, the pans will not be unloaded until you perform that step yourself.
Check AutoLid II installed if you have a DSC Q2000/Q200 instrument or have upgraded your older instrument to the Q2000/Q200 model.
Check or uncheck the Event (RCS) Off box to control the state of an external device (Refrigerated Cooling System--RCS) connected to the instrument with the event cable at the end of the Autosampler run sequence.
Check the box to turn the event device (RCS) off at the end of the last Autosampler run in the sequence. This allows you to leave the RCS running during all of the methods in the run sequence, but turn it off at the end of the run sequence.
Uncheck the box (the default condition) to leave the event device (RCS) in the state it was in at the end of the run sequence. If the RCS was on at the end of the run sequence, it will remain on, if this box is left unchecked.
NOTE: In the event that the run sequence is stopped due to an error, the RCS will automatically be turned off, regardless of your selection, to prevent frosting.
Check or uncheck the LNCS Off box to control the state of the LNCS at the end of a sequence.
Check the box to turn the LNCS off (default condition) at the end of the last Autosampler run in the sequence. This allows you to leave the LNCS running during all of the methods in the run sequence, but turn it off at the end of the run sequence.
Uncheck the box to leave the LNCS in the state it was in at the end of the run sequence. If the LNCS was on at the end of the run sequence, it will remain on, if this box is left unchecked.
NOTE: In the event that the run sequence is stopped due to an error, the LNCS will automatically be turned off, regardless of your selection, to prevent frosting.
Use the Instrument Preferences/Autosampler page to continue or halt the sequence when a recoverable error occurs. Select the radio button next to the desired setting to turn it on (click for a definition):
Select to have the Autosampler attempt to continue operation when it encounters a recoverable, nonfatal error condition (such as not picking up a sample pan from the platform). Two attempts will be made to pick up a pan, if unsuccessful, the sequence will continue to the next run in the sequence. An error entry will be added to the instrument log.
Select to have the Autosampler suspend all further operation when it encounters any Autosampler error condition. When an error occurs, you must first correct the problem, then you can restart the sequence from that point. An error entry will be added to the instrument log.
NOTE: Changes made to these settings during the last run of the sequence will not have an effect until the next sequence.
If you prefer to work with the DSC without using the Autosampler to load pans, you may do so by disabling the Autosampler. This can be done using one of these methods:
Select the Instrument Preferences/Autosampler page, then uncheck the option Enable Autosampler.
Select Control/Autosampler/Enable, then uncheck the menu item. (If there is a check mark next to Enable, the Autosampler is enabled and will operate as normal.)
See also: Running an AS as a Non-AS
NOTE: The Autosampler may not be disabled during an active sequence.