Measuring Square or Rectangular Tube
From ATTWiki
ROMER-CIMCORE DOCS and Supravision software packages use non-contact infrared probes (sensors) that can measure tube, pipe, or rod that are bent. Customers sometimes ask if rectangular or square tube can be measured using the same non-contact sensors. This is the method recommended by Romer:
Measuring Center Adapter
In order to simulate a cylindrical shape, it is necessary to change the shape of the square or rectangular tube using an adapter that is designed as shown in this image.