Chapter 8 Ensuring Repeatability, Accuracy, and Resolution
Optimizing Repeatability From One Calibration to the Next
Getting Started Guide 8-13
8
Optimizing Repeatability From One
Calibration to the Next
Repeatability is a measure of consistency from one calibration to the next
(see Figure 8-1). The metrology software helps you make consistent
measurements by enabling you to recall saved setup files and open online
setup diagrams. Make your measurements carefully and follow these
guidelines:
• Set up the measurement the same way each time.
• Keep your deadpath consistent. Use the same distance between optics
each time.
• Place the sensors in the same place each time.
• Standardize the machine environment; for example:
– Match the conditions surrounding the measurement as closely as
possible from one calibration to the next.
– Be sure the machine’s foundation is rigid and will not move with
the machine’s motion.
– Keep the temperature around the machine as stable as possible.
Remember, unless your work area is temperature-controlled, the
temperature may change as you travel up from the machine’s base
as well as along the machine’s length.
– Use the same optics and environmental sensors from one
calibration to the next.
• Attach the measurement and reference retroreflectors to the
interferometer. Then, watch the measurement display for any
fluctuations indicating noise from the electronics.
Noise from the electronics is rarely a problem and you normally will
not see any fluctuations.