The QC (Quality Control) window in 4D's 4Sight analysis software is a
convenient interface for performing measurements to verify system and setup
repeatability. To view
this screen choose Measure > QC
Measurement.
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| The QC (Quality Control) Screen in 4D's 4Sight Analysis Software |
Typically, a QC measurement consists of multiple Averaged Measurements. You can specify:
- The number of measurements to acquire
- The number of runs to average for each measurement. In most cases 8-10 measurements and 16 averages per measurement yields useful results
- The time delay between measurements.
You can also specify Acceptance Criteria for individual measurements acquired during the
run. If a single measurement fails to meet all the acceptance criteria, for
example because of vibration or air turbulence, then the measurement will be
repeated.
For each measurement statistics are
displayed in the upper right of the screen:
PVr The Robust Peak-to-Valley
height, The Robust Peak-to-Valley statistic (PVr) is the peak-to-valley
difference of a 35 term Zernike fit + 3*RMS of the residual (the dataset minus
the 35-term fit).
RMS The root-mean-square roughness.
Delta PVr The Robust Peak-to-Valley
height calculated for each delta (rather than each measurement).
Delta RMS The root-mean-square roughness
calculated for each delta (rather than each measurement).
The QC Screen also calculates the following statistics.
“Average surface” refers to the average of all measurements, as seen by clicking
the View Average button:
Uncalibrated Accuracy The PVr and RMS calculations for the average surface.
PVr Repeatability The
standard deviation of the PVr calculations for the individual averaged
measurements.
RMS Repeatability The
standard deviation of the RMS of the averaged measurements.
PVr Precision The
mean of the PVr calculations for the delta measurements.
RMS Precision The
mean of the RMS of the delta measurements.
