Inside Diameters on O-Inspect

[[To...]]

We measure inside diameters on stamped parts that are 1.4mm thick on an O-Inspect. For some reason the diameters measure 0.10mm smaller than what we get when using pin gages. I have tried several different evaluation calculations to see if it would make a difference. Any assistance would be greatly appreciated.

[[Ri...]]

Put a gage pin in a suspect part.
View thru the hole with pin in place and see if its a form issue.

[[Cl...]]

With thin material like that, there might be some bending or
waviness near the hole. This could possibly influence the size.

[[No...]]

How big are the holes and which zoom factor are you using?
The camera has one zoom factor that is telecentric (on our's it's the 1.61x). Telecentric means that the camera image has no parallax errors near the edges. Other zoom factors, especially lower ones, feature these parallax errors, possibly resulting in distortion and wrong edge detection if the feature is not measured at the center of the FOV.
Since Calypso is now able to measure several features in one image without moving, small features near the edge of the FOV may become distorted. Hence my question above.

[[To...]]

The diameters range from 8mm to 11mm and we are using the 0.5x zoom on the camera. I will look into this and try different magnifications.

[[Ri...]]

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Yeah. I try to not use that low of a mag to measure anything. I typically only use it for part setup location. The lower the mag, the lower the accuracy.

1.61x and up are the best magnifications.