Tecnai on-line help manual -- Options - UT Southwestern

<strong>Tecnai</strong> on-line help Options 84Options Software version 2• Find a recognizable specimen area at X ~ 0 and Y ~ 0. Execute a calibration. The data for the holderwill now list where the X position of the β tilt axis lies.• Find a recognizable specimen area at approximately X shift -400 µm. Select Replace to replace theearlier calibration (whose X and Z positions are usually reasonable but the A and C skews tend to belarger than realistic) and perform a new calibration.• Find another recognizable specimen area at approximately X shift +400 µm. This time select Add (orCompare) and Add another point to the calibration.Note 2: All β tilts set by the calibration procedure will be executed compucentrically. That means that theimage feature selected should stay reasonably close to the center of the screen, unless the currentholder calibration is far off (which may be the case when starting from the default settings).Start buttonThe Start button starts the calibration procedure. The software instructs the operator to set the β tilt closeto 0 and center the recognizable image feature.Instructions panelThe instructions panel gives instructions during execution of the calibration procedure.Continue buttonThe Continue buttons leads to the next step of the calibration procedure. When the procedure is finished,the calibration parameters and residual are calculated, dependent on the option Replace, Add orCompare chosen. After the procedure the stage is reset to the position (and tilts) at which the calibrationprocedure was started.Cancel buttonThe Cancel button cancels the calibration procedure. The stage is reset to the position (and tilts) atwhich the calibration procedure was started.ReplaceIf a calibration already exists, the Replace option is enabled. When this is selected the new calibrationwill replace the earlier calibration (all points).AddIf a calibration already exists, the Add option is enabled. When this is selected the new calibration will beadded to the earlier calibration. If ten points were already present, the first point is deleted and all pointsare shifted down one to make room for the data of the new point.CompareIf a calibration already exists, the Compare option is enabled. When this is selected the two newcalibrations will be calculated, one in which the new calibration is used only (Replace) and one in which itis added to the earlier calibration (Add). The Cal. data tab will become active and the data are displacedside by side. Choose an option (Replace or Add) and press Continue.