What is the measurement plane on the Mentor Visual iQ+ VideoProbe? 

In this article:

• Explains what the measurement plane is on the Mentor Visual iQ+ VideoProbe and how it mathematically extends a flat 3D reference surface to improve measurement accuracy when 3D data is missing or noisy. 
• Shows where the measurement plane adds value in remote visual inspection, including blade edge damage, missing corners, small features, and flat-surface pit analysis using multiple 3D measurement types. 
• Details how the measurement plane interacts with different 3D measurement tools (length, depth, area, angle, radius), clarifying when and how it should be used on flat reference surfaces. 

What is the measurement plane on the Mentor Visual iQ+ VideoProbe?

Measurement aid used in conjunction with other measurement types to allow the placement of cursors in red areas where no 3D data is present or where noise in the 3D data may be reducing measurement accuracy. This is accomplished by mathematically extending the measurement plane into 3D space.

Example Applications:

• With Area or Missing Corner to measure blade missing corners
• With Point to Line for blade edge damage
• With Depth for blade tip to shroud gaps
• With Length or Point to Line for small features when unable to get closer
• With Area Depth Profile when measuring a field of pits on a flat surface
• With Depth Profile when you cannot fit the cursors fully on a flat reference surface
• With Radius Gauge to assess boroblend edge radii

Effect of a Measurement Plane on other measurement types:

• Length, Point to Line, Multi-Segment, and Area: All cursors are projected onto the Measurement Plane, and the result is computed using the projected positions on the plane.
• Depth: The first three cursors select individual surface points as with a normal Depth measurement. Only the fourth is projected onto the Measurement Plane.
• Depth Profile: The Measurement Plane is used as the reference plane, so the Depth Profile cursors may overlap edges or be in red areas. The result is the height or depth from the Measurement Plane. Use only with flat reference surfaces.
• Area Depth Profile: Both reference lines are positioned on the Measurement Plane allowing them to pass through red areas or surface pits without affecting the profiles taken between the reference lines. The result is the height or depth from the Measurement Plane. Use only with flat reference surfaces.
• Angle: All three cursors are projected onto the Measurement Plane.
• Surface Angle: Only the fourth cursor is projected onto the Measurement Plane. The first three cursors still separately define the reference plane.
• Missing Corner: Requires prior placement of the Measurement Plane, and all cursors are projected onto the Measurement Plane.
• Radius Gauge: The Radius Gauge circle is placed on the Measurement Plane.
• Only one Measurement Plane can be used on an image.
• If a Measurement Plane is present, all other measurements use it regardless of the order in which they were placed.