Setting Up Calibration StandardsSetting Up Calibration Standards
This function is used to define the default settings for each DSC calibration standard, add new standards, and reset (reload) the default calibration table. These settings include: the theoretical values for the standard, definitions of the limits that will be used for calibration analysis, and the default method that will be displayed as the procedure when this calibration standard is selected.
Access the DSC Calibration Standard window using one of the following methods:
Select Calibrate/Analysis from the main menu. The Calibration Analysis window is displayed. Click the Setup button.
Place the instrument in calibration
mode on the Summary
Page. Click the 
button to make changes to the settings
for the calibration standard.
Then set up the calibration standard as follows:
Select the Standard Name from the drop-down list to edit or verify its default parameters displayed on this window. To add a new standard to this list, type in a new name and define its settings. This standard will be saved when you click the OK button.
Enter the literature Melting Point in °C. Consult your Chemistry handbook for the value.
Enter the Heat of Fusion in Joules/gram. Consult your Chemistry handbook for the value.
Enter the desired Lower Limit to be used for the calibration analysis, the starting point to begin gathering data.
Enter the desired Upper Limit to be used for the calibration analysis, the ending point to stop gathering data.
If you want to change the method, select the desired Start temperature by either checking Use current or entering the desired starting temperature. Check this box to use the temperature of the DSC cell at the current moment (usually ambient temperature, 35°C). In this case, the ramped heating begins immediately on starting the experiment.
Enter the Heating rate that you want to use.
Enter the desired heat rate to be used. The acceptable range of heating/cooling rates for conventional DSC is 0.01 to 100°C/minute. This range depends on a number of variables including the temperature range covered and the presence of a cooling accessory. Faster heating/cooling rates generally increase sensitivity, particularly for thermal events such as the glass transition. They also obviously shorten the time of analysis. Slower heating/cooling rates generally provide better resolution (separation of closely spaced thermal events). Heating rates of 10 to 20°C/minute and cooling rates of 5 to 10°C/minute are a good starting point for most materials.
The temperature range of analysis for the DSC cell is -180 to 725°C. However, the range that is usable in a specific experiment depends on the cooling accessory and the type of sample pan being used. To evaluate materials below room temperature or to run cooling rate experiments, the DSC cell requires a source of external cooling. In addition there are multiple types of DSC pans available. All of them are acceptable for use to 725°C except for aluminum pans, which should only be used to 600°C (aluminum melts at 660°C).
Enter the Final temperature.
Enter the final temperature for your experiment that is within the usable temperature of the DSC/cooling accessory combination that you are using. The starting and final temperatures should bracket the region where sample transitions are expected to occur and they should be far enough below or above the transitions to establish a stable baseline.
The temperature range of analysis for the DSC cell is -180 to 725°C. However, the range that is usable in a specific experiment depends on the cooling accessory and the type of sample pan being used. To evaluate materials below room temperature or to run cooling rate experiments, the DSC cell requires a source of external cooling. In addition there are multiple types of DSC pans available. All of them are acceptable for use to 725°C except for aluminum pans, which should only be used to 600°C (aluminum melts at 660°C).
Select OK to save the changes. Any entries that are made here will be saved for future recall.
NOTE: To return the standards list back to the default values, click on the Default button. See also: Resetting the Calibration Settings
NOTE: The Delete button can be applied only to a standard that you have entered. You cannot delete the program standards.
In the event that you want to restore the entire calibration table back to the original manufacture defaults (set at TA Instruments), click on the Reset All button. A confirmation message will be displayed. Select Yes to continue operation or select No to cancel the reset function.
