FARO Edge
September 2012
75
Chapter 5: Accuracy
Chapter 5: Accuracy
This chapter describes the definitions and specifications of accuracy, or
performance specification, for the Edge.
The Edge performance testing standard is the North American ASME or
European ISO standard. Edge test methods are a subset of those given in the
B89.4.22 standard. Single-point repeatability is measured using a hard probe in a
reference hole. Volumetric performance is measured using a traceable length
artifact. Measurements are well distributed in all regions of the working volume.
Compensation and Calibration
The Edge is designed to endure the typical stress and impact loads of a “factory
floor” measuring tool, as well as survive multiple transportation cycles while
maintaining its accuracy throughout its usable life. In order to fully appreciate
what is meant by “Lifetime Calibration,” you must first understand several basic
concepts of measurement equipment.
Compensation versus Calibration
In most cases, the terms “compensation and calibration” are used together, and
are often mistakenly used interchangeably. This generally occurs because
traditional Coordinate Measuring Machines are often compensated every time
they are calibrated. In reference to the Edge, there are two types of compensation:
the Edge compensation and the probe compensation.
Edge Compensation
Compensation is the procedure by which a measurement device is optimized to
perform accurate measurements. This may be done through mechanical
adjustments, as well as software corrections.
Specialists at FARO’s production facility perform the factory compensation. This
compensation utilizes patented hardware and software (not available to the user)
to determine the true dimensions and kinematics of the Edge. The results of the
factory compensation are imprinted to memory located in the Edge electronics.
The Edge is permanently compensated, such that it does not require mechanical
adjustments during normal operation.
The Edge compensation becomes invalid (stop functioning within FARO's
published standards) if one or more of the following occurs:
• Bending of the transfer cases (long, tube sections).
08M52E00_FaroArm_Edge.book Page 75 Thursday, October 4, 2012 9:31 AM