Title: CRC-1: Evaluation of F-Number Systems and Waviness Index for Measuring Floor Flatness and Levelness
Author(s): James C. Wambold and Charles E. Antle
Publication: Technical Documents
Appears on pages(s): 10
Note: CRC-1 is No Longer Available.
Most of the critical comments and reviews of the two methods provided to the authors as background are generally not justified. There is indeed much in common in the two methods. It is surely true that both leave room for improvements in the future. In general, the weights to apply to the various wavelengths must be set for the intended purpose. Both the user and contractor should jointly set these requirements. Then and then can the proper method of elevating the levelness and flatness be established. In the case of the F numbers the value of the FF number is a measure of the flatness (measuring amplitude at short wavelenghts and curvature at longer wavelengths), while the FL measures the levelness. The Waviness Index extends the measurement of the amplitude of longer wavelengths. The method of pooling is new but appears to be proven using variograms. The resulting spectrum weights for either method are of no known statistical requirements (for vehicles, ride quality, etc), but do provide for equal weighting. It is our conclusion that either system is consistent on it's own and should produce repeatable results. It would appear the customer and contractor should be allowed their choice. However, in the future, consideration should be given to a combination or to other analysis such as an ampliitude spectrum analysis. Then the spectrum weighting required for the intended use could be set.