Calibrating the DSC

To obtain accurate experimental results you should calibrate the DSC cell when you first install it.  For the best results, you should recalibrate periodically.  The calibration procedures that you need to perform will vary depending on the instrument model and heat flow selection. These experiments will be performed using the instrument control software. See the chart below for a general guide to types of calibration.  For details on how to perform that calibration, refer to linked topics in this section.

The various calibration procedures can be performed several different ways, depending upon the DSC instrument in use.

• DSC Q2000, Q200, and Q20 instruments can be calibrated using the Platinum™ functions, the Calibration Wizard, or manually using the templates.

• DSC Q1000, Q100, and Q10 instruments can be calibrated using the Calibration Wizard or manually using the templates.

Calibration consists of several different types of procedures specific to each cell, which are described briefly below.  

Select from the following topics for more information:

• When to Calibrate

• Calibrating the T1 Baseline (T1 Heat Flow)

• Calibrating Tzero (T4 and T4P Heat Flow)

• Calibrating the DSC Enthalpy (Cell Constant) and Temperature

• Calibrating DSC Heat Capacity

• Baseline Conditioning

• Cell/Cooler Conditioning

• Pressure Calibration

• Calibrating Using the Platinum Functions (Q2000/Q200/Q20 Only)

• Indium Tracking

NOTE:  At initial installation of the DSC, RCS, or LNCS or after the DSC has been shut down for more than 24 hours. It is recommended that the system be "conditioned" before you start calibration. Click here Setting Up a DSC Cell/Cooler Conditioning Procedure for details on the conditioning procedure.

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*  Tzero™ describes proprietary technology invented by Robert Danley of TA Instruments—Waters LLC and patented by TA Instruments—Waters LLC (U.S. Patent No. 6,431,747).

** Heat Capacity calibration is NOT performed in cal mode and is not required except when making absolute measurements of heat capacity.

NOTE:  Perform calibration runs that encompass the temperature range you plan to use in your experiments. (We recommend calibration over the widest temperature range.) If your subsequent experiments cover a wider range, you may wish to recalibrate.

NOTE: Please make sure that you run your experiments with the same gas that you used to calibrate the system. For example, if you calibrate using nitrogen, make your runs with nitrogen.

Calibration results may be viewed in the Cell/Temperature Table window and by using the Calibration Report.

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When to Calibrate

For optimum experimental results you will need to perform all DSC calibrations whenever you change one of the following parameters:

• First use of a new cell

• Purge gas change

• Cooling device or accessory (FACS, LNCS, RCS, or Quench Cooling Can) change

For optimum experimental results you will need to perform all DSC calibrations except Tzero whenever you change one of the following parameters:

• Heat flow selection change (T4P, T4, etc.)

• Pressure (in PDSC experiments) change

Calibration is performed in the instrument’s calibration mode, which is accessed through the Experimental View/Summary Page.  (This does not apply to heat capacity calibration, which is performed in both the standard and MDSC modes, where applicable).

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Pressure Calibration

Pressure calibration is an optional calibration procedure for the pressure DSC cells.  It is based on comparing the pressure reading at two points, typically one atmosphere and another pressure selected by you, to the pressure reading on an external pressure gauge.

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