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

<strong>Tecnai</strong> on-line help Options 67Options Software version 2Use Other keysAdditionally a few other keyboard keys can be used:• Enter key: Add location• Space key: Next holeColorsThe four types of colors (Background, Foreground, Holes, Locations, Current location) for the displaycan be freely selected. The selection is made in the Control options dialog or by clicking on the windowwith the right-mouse button. The latter will popup a menu that allows definition of the colors.Note: There is one exception to free color selection: if hyperlabels are used the Location color cannot beblue (this is the flash color of the hyperlabel).4.8 Calibrate gridCalibration is the setup step wherein the software is informed about the dimensions and orientation ofthe grid. This is done by moving three points to the center of the screen with the specimen stage. Thesoftware will show a dialog with one of the following schematic drawings of a part of a grid.The three calibration points lie on opposite sides of a grid hole (1, 2) and in the next grid hole (3). Thechoice of the points doesn't matter (for instance, 1 and 3 can be closest to the operator, 2 furthest away);what counts is their relation.After the third point has been entered the software knows the size of a grid hole, the orientation and theshift necessary to go from one hole to the next.The software then will drive the stage to a grid hole 750 µm away from the current position, where apoint similar to number 1 must be found. From the position of this point, the software fine-tunes thecalibration. If no fourth point can be identified with certainty, simply press OK without moving the stage.4.9 Reference pointsReference points are locations on the specimen that are easily recognized and can be used as referencewhen the specimen is removed from the specimen holder and later put back in again. By finding thereference points again, the software can recalculate the old locations to new ones.Reference points should be located close to but not at the periphery of the specimen. Locations furtherfrom the center increase the accuracy of relocation but if a reference point later lies outside the reach ofthe stage, then it is not possible to recalculate the old locations to new ones. Because specimens areoften shifted up to 0.2 mm when re-inserted into the specimen holder, keep the reference points lessthan 800 µm away from the center.Setting the reference points can be done at any stage of Grid Scanning (but before the data are savedinto a file, otherwise the reference points are not included in the file). When an old file containing