Can 2.5D VMM with touch probe as replacement to CMM?

Most people aware that the dimension of 3D is refer to [Width x Depth x Height] while 2D is refer to [Width x Depth] of an object.
How about 2.5D VMM and what are the differences?
Today, let us share some general knowledge on this topic.
2.5D VMM is a combination of VMM with Optical Touch Probe which consider as enhancement device for certain measurement requirement such as inner or depth dimension, for the view of workpiece that cannot be captured & focused clearly with using camera system.

Someone might ask… “Is the function of touch probe similar with CMM?”
We couldn’t say “NO”, but it is different in certain criterions.
First, the Z-axis height will be different compare with CMM & VMM. CMM usually targeted by using bigger, higher height part while VMM is limited and usually used for workpiece height below than 200mm.
Next, the probe of VMM is fixed only in one position within Up & Down movement, whereas CMM can change the position from different angle degrees, e.g., Different types of probes (PH10T or MH20i) able to adjust the different position flexibility.

Furthermore, the measuring range of touch probe for VMM will be smaller. For instant, if the VMM capability of measuring range is 300 (X) x 200mm (Y) then the X axis of touch probe will approximately be 200mm. This deviation of the fixed position is come from the camera zoom lens and Touch Probe.

In conclusion, every machine has its own unique advantage.
If your sample has different height of profile in critical dimension, you are suggested to go for CMM because all the dimensions are taken by the probe system.
If people who required touch probe to measure some shallow depth dimension on their sample but they have budget concern then 2.5D VMM will be their prior choice.
Above sharing just for your reference. When you’re interested in investing a VMM or CMM to improve your quality process, select a supplier who offer a quality service and meet your specific needs.
If you have any enquiry with VMM or IMM machine, welcome to contact us by email: enquiry@mspmetrology.com
Jun 21,2023