PerkinElmer STA 8000, Инструкция по установке и эксплуатации оборудования

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52 . STA 8000 Installation and Hardware Guide
DTA Baseline Optimization
This optimizes the Differential Thermal Analyser scanning baseline between two
temperatures selected by the user. The resultant DTA curve is fitted to an equation that
flattens the baseline. The process takes 1–2 hours.

In the DTA Baseline Optimization screen, enter the
Start Temperature
,
End
Temperature
and the
Scan Rate
, and then click
Run Calibration
.
Select start and end temperatures which include the range you will use for your
measurements. It is important to choose a start temperature below that which you will
use in experiments to ensure that the baseline optimization covers the full range of
temperatures needed. Use a scan rate that you plan to use for most analyses;
suggested values are 10–20 °C/min.
TG Drift Optimization
This process corrects for the variation in weight measurement that occurs as the temperature
of the balance alters during an experiment. The balance temperature is affected by the
cooling device used with the analyzer. We recommend that you carry out the TG Drift
Optimization when the instrument is first installed. Subsequently, it should only be repeated
if you change the cooling system.

In the DTA Baseline Optimization screen, click the box marked
Perform TG drift
optimization (~8 hours)
.
The optimization routine will be performed using a predefined method (not the same
method as the DTA Baseline Optimization). Since the procedure takes approximately
8 hours to complete, we recommend that you run it overnight. If the option is selected,
Pyris will run the TG Drift Optimization followed automatically by the DTA Baseline
Optimization.
Temperature and Heat Flow Verification
During normal use, it is usually only necessary to verify that the existing calibration gives
accurate data by running a test with a standard and checking that the temperature and heat
flow measurements agree with the accepted values. An example of a suitable procedure is
given below.
NOTE: The recommended calibration standards for temperature in the STA 8000 are indium,
aluminum and gold. The user can substitute these for different standards using the
calibration wizard in the Pyris software. Palladium should be used instead of gold for
experiments where the temperature exceeds 1300 °C. The recommended calibration
standards for heat flow are indium and gold/palladium. Refer to the Pyris software
Help for more information.
1. Place empty sample pans onto both platforms of the sensor, and tare the weights.
2. Place a piece of the standard (10–20 mg) into the sample pan (on the left side of the
sensor) and record the weight.
The weight can also be entered manually in the Method Editor.
3. Create and run a method to heat the sample in excess of its melting temperature at a
scan rate of 20 °C/min.