Geometry Triggers

Geometry Trigger

Geometry Trigger mode allows you to define planar, cylindrical, or spherical cross sections that, when crossed by the probe, trigger measurement. By default, these geometric triggers are not defined. You first need to define them by right-clicking on the Geometry Trigger button, which will take you to the Make Geometry Crossing Triggers dialog. The top of this dialog (separated into Add Planes, Add Cylinders, and Add Spheres sections) is where the geometry triggers are defined. The active geometry triggers are displayed in the list in the center of this dialog.

 

Add Planes:


In this dialog, check the axes along which you’d like to create planes, and also specify their start and stop position (in active units), as well as their spacing. In this example, planes will be placed along the active Z axis, from Z=0” to Z=20”, spaced by 2” (see image above).

It is important to realize that, due to a number of limiting factors such as hardware sampling speed and computer speed, the sampled data will almost never be taken exactly on the geometry’s boundary. In the Cross Sampling section, choose Interpolate to have SA interpolate between two sampled points on each side of the geometry trigger, and Closest Pt. to have SA use the closest sampled point to the trigger. The Interpolate option will result in a point lying directly on the geometry trigger (although it will not have been an actual sampled point), whereas Closest Pt. will be a true sampled point, but will likely not lie directly on the defined trigger.

You can also specify the width and height of the planes (for drawing purposes only) if they are going to be drawn in the graphical view.

It is important to realize that, due to a number of limiting factors such as hardware sampling speed and computer speed, the sampled data will almost never be taken exactly on the geometry’s boundary. In the Cross-Sampling section, choose Interpolate to have SA interpolate between two sampled points on each side of the geometry trigger, and Closest Pt. to have SA use the closest sampled point to the trigger. The Interpolate option will result in a point lying directly on the geometry trigger (although it will not have been an actual sampled point), whereas Closest Pt. will be a true sampled point, but will likely not lie directly on the defined trigger.

 

You can also specify the radius (width) and length of the planes (for drawing purposes only) if they are going to be drawn in the graphical view. The settings in were used to create the trigger planes.

 

Add Cylinders

This section is used to add cylindrical geometry triggers.

 

 

Add Spheres

This section is used to add spherical geometry triggers.

 

 

Trigger List

The Make Geometry Crossing Triggers dialog displays a list of the currently active triggers. You can single or multi-select active triggers, then remove them from the trigger list using the Delete Selected button. Or, you can delete all active triggers using the Delete ALL button.