Discovery TGA™ Getting Started Guide
Page 57
Calibrating the Discovery TGA
To obtain accurate experimental results, you should calibrate the instrument upon initial installation. For
the best results, however, you should recalibrate periodically.
Several types of calibration are required for the TGA: Autosampler or Autoloader, weight, and temperature
calibration. A brief description is provided below. Autosampler/Autoloader calibration is performed via
the instrument user interface. Weight and temperature calibration are performed through TRIOS software.
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 consists of several different types of procedures that are described briefly below. For more
details on performing each type of calibration, refer to the instructions in TRIOS software Online Help.
Autosampler and Autoloader Calibration
Perform an Autosampler or Autoloader calibration after initial installation of the system, and calibrate
periodically thereafter as needed.
If the Autosampler fails to pick up a sample pan correctly during an automatic loading procedure, the
Autosampler may need to be calibrated.
If the Autoloader fails to pick up the sample pan correctly, the Autoloader may need to be calibrated.
Other possible causes for improper pan pickup include:
•
The instrument is not level. See
“Leveling the Discovery TGA and Aligning the Balance” on page 45
for instructions to solve this problem.
•
The hang-down wire is not straight. Replace the hang-down wire; see
for instructions.
•
The bails on the sample pan are bent. If possible, straighten them or use new pans.
To perform Autosampler or Autoloader calibration, access the Autosampler or Autoloader panel on the
user interface. Refer to TRIOS software Online Help for detailed instructions.
Weight Calibration
Weight calibration is required upon initial installation of the system. After the initial weight calibration,
weight calibration should then be done periodically (once a month is recommended). This calibration can
be performed manually (using an empty pan and calibration weights) or automatically (using the three
weight calibration pans).
•
Semi-automatic weight calibration
is performed using known calibration weights, typically 100 mg
and 1000 mg. This procedure involves weighing a pan with and without the calibration weights to cal-
ibrate the low and high weight ranges. This procedure is conducted through TRIOS software using the
Calibrate
function and clicking on the
Weight Calibration
and
Semi-Auto
tabs.
•
Automatic weight calibration
is accessed through TRIOS software by using the
Calibrate
function
and clicking on the
Weight Calibration
and
Auto
tabs. In this case the pan differential is used to cali-
brate the weight. The weight calibration pans may only be used when a platinum tare pan is installed.
See TRIOS software Online Help for more information on weight calibration of either type.
