Nanometer Optical Measuring System (NOM)
Crystal Scientific have an autocollimator based metrology system, a Nanometer Optical Measuring system (NOM). This is are set up on the same air beam as the LTP which allows comparative LTP and NOM measurements to be made along the length of a mirror up to 1.4 m without having to adjust any of the optics.
The NOM was purchased in 2009 and is similar to that at the Diamond Light Source and other synchrotrons. This provides more accurate and reliable measurements than the LTP – critical when producing mirrors with sub microradian slope errors. The Crystal Scientific NOM has been compared against the system at the Diamond Light Source. See Data for the comparison graph.