TriNano is a new nano/micro CMM to measure objects with sub-millimetre features in three dimensions and with nanometre uncertainty. In order to reach nanometre uncertainty while keeping the device cost efficient, a new working principle has been developed. This principle employs a moving work piece table and a stationary probe. The table moves in three directions by means of three identical linear translation stages.
These stages are positioned orthogonally and in parallel (like a tripod). On each linear stage, the scale of an optical linear encoder is mounted. At the point of intersection of the measurement axes of these encoders the probe tip is located. As the orientation of the encoder scale does not vary with respect to the probe, the TriNano complies with the Abbe principle over its entire measurement range.
Besides the obvious cost savings when manufacturing three identical axis, this configuration enables fast measurements through its superior dynamical behaviour. Furthermore, complying with the Abbe principle in 3D greatly reduces non repeatable errors and enables a TriNano N100 to reach a 3D uncertainty of 100 nanometre over its entire measuring range.