FARO was awarded U.S. patent #5,402,582, with worldwide patents pending, for the concept and methods of temperature compensation for portable CMM devices. This overview provides a general description of how the temperature compensation works.
To maintain certified accuracy in a various environments, all FaroArms continuously monitor temperature and its rate of change over time. The latest FaroArms employ a software and hardware solution with a semiconductor temperature sensor built into each joint. Legacy models of FaroArms also employ software and hardware solutions with a semiconductor temperature sensor is built into the point of largest mass. This position is critical because it is the last place on the FaroArm to stabilize after a temperature change.
For all models of FaroArms, the rate of temperature change is applied to mathematical formulas or kinematics, which define the position of the FaroArm in three-dimensional space. Link length corrections are made constantly by the inboard processor, which adjusts the kinematics and adapts the output to the changing environmental temperature. For your convenience, the electronics system is programmed to generate an error message when the temperature exceeds a ±3 degree bandwidth. There is also a built-in routine that establishes temperature stability, whereby the device monitors itself for five minutes and indicates when it is ready to use.
Because different components heat up and cool down at different rates, to maintain accuracy your FaroArm must be at a steady state temperature within ±3° Celsius for five minutes before taking measurements.You can monitor the temperature status in your measurement software, such the FARO Edge onboard software or Measure and later.
Caption: Temperature Dialog Box
Refer to your user guide for details regarding how to work with temperature settings.