Commands and Tips for Thermo Scientific Devices
ThermoQuest/Thermo Scientific TRACE GC (2000/Ultra): Setting the Temperature

Entering a Temperature Gradient

To enter a temperature gradient, use a Program.

For the TRACE GC (2000/Ultra), a temperature profile can be entered with a maximum of six ascents or descents. The maximum temperature change (ascent) is up to 120°C per minute (1200°C/min for the TRACE UltraFast), depending on the oven type.

Gradients are entered in the Program Wizard in the typical format for GC applications. (The starting and end temperatures are entered, as well as the modification rate.) In the program, however, the "base point philosophy" is used (similar to entering a flow or percent gradient in HPLC). Each temperature command is the base point of the gradient program. The wizard automatically converts the entered rates into the base point representation.

An Inject command is indispensable. No gradient is executed before the Inject command. Thus, temperature gradients can only begin after the Inject command.

Temperature Setting

Reaching the nominal temperature on the instrument can take some time. Please note that the oven heats faster than the injector and the detector system. As soon as all temperatures and the specified pressure and flow parameter are reached, the GC sends a Ready signal. An injection from the autosampler is possible only after this signal.

Example:

The following program waits until the nominal temperature (150°C) is reached before the Inject command is executed:

  0.000 GC.Temperature = 150

   Wait GC.Ready

   Inject

  ...... ..............

 Tip:

After the instrument has received the method parameters from Chromeleon, it implements the desired value as quickly as possible. When the value is "almost" reached, the Equilibration Time passes until the instrument sends the confirmation message to Chromeleon. You can specify the duration of this time interval, using the Equilibration Time parameter in Chromeleon.