PerkinElmer TGA 8000, Инструкция по установке и эксплуатации оборудования

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88 . TGA 8000 Installation and Hardware Guide
Sample Handling - TGA 8000 Autosampler
The TGA 8000 measures the change in weight of a sample as a function of temperature or
time. Proper sample preparation and handling are important for obtaining optimal results.
Sample Preparation
The thermogravimetric analyzer analyzes solid samples in powder, crystal, or granular form.
Although quantitative accuracy will remain the same regardless of sample shape, the
qualitative appearance of a run may be affected by the sample configuration. Proper sample
preparation that maximizes the contact surface between the crucible and the sample will
reduce any imbalance of the sample in the crucible and will result in maximum peak
sharpness and resolution. The best sample form for optimum performance is powder or fine
granules. Solid materials can be sliced into small pieces with a razor or knife.
Sample Pans
The sample tray holds up to 48 crucibles. You can also place an aluminum liner (P/N N5370492)
or a stainless steel liner (P/N N5370495) within the crucible to lengthen its usability. The liner can
be used for runs under 600 °C.
Sample Atmosphere
Once the sample is loaded onto the hangdown wire and the autosampler returns to the Safe
position, the sample is subject to the same atmosphere as a sample in a standard TGA 8000.
The furnace rises up around the sample and the sheath gas, if used, baths the furnace liner;
that is, the gas goes between the Pyrex furnace tube and the liner, not in the furnace.
Sample Loading
Before loading the samples into the crucibles, you will have to tare the crucibles, that is,
have the system weigh them so the weight of the crucible is not included in the data. Load
the empty crucibles into the sample ring. You can do this with the ring off of the autosampler
assembly. After filling the locations, carefully place the ring over the gripper and settle the
ring into position. There is a locating pin in the autosampler that goes into the hole in the
tray. You could also keep the ring on the autosampler and use tweezers to load the crucibles
into the ring. Make sure that the autosampler is in the Safe position. Be careful with the
tweezers around the hangdown wire.
You can tare all of the crucibles in the tray using the Pyris Player Tare All feature. Your play
list should contain a Sample Group. If you are creating a new play list, select Sample
Group as the first entry. If you are using an existing play list, it should have a Sample Group
in it. In a new play list, with Sample Group highlighted, click the Tare All button to display
the Advanced Tare Options dialog box. The tare weights are automatically put into the
Sample List. If you chose Populate from Tray in the Advanced Tare Options dialog box,
the Sample List is filled with a line for each position in the sample ring that contains a
crucible and the tare weight of the crucible is included.