It all started with LW and SW in the early 1990s. BYK-Gardner´s well-known wave-scan analyzes waviness based on wavelength range and its intensity.
The LW-value integrates waviness in the range of 1.2 – 12 mm and the SW-value sums up fine textures in the range of 0.3 – 1.2 mm. As material and process parameters changed, these integrated parameters were not always sufficient to differentiate various surface appearances.
Consequently, in 2001 the next generation, wave-scan DOI was introduced measuring 5 wavelength ranges as well as the distinctness of image. These six measurement parameters are graphed and called a “structure spectrum”, which is an ideal guide for trouble shooting and optimizing surface appearance based on material or application influencers.
In 2012, a new approach was initiated within the VW/Audi group and was first presented at our BYK-Gardner User Meeting in 2013.
The results are weighted according to the VW / Audi study to simulate an observation distance of 1.5 m.
Dominant SW = 1.3 mm
Dominant SW intensity = 13.6