Layers created by the SpreadStation are analyzed using three independent measuring systems and produce three independent sets of data. The measuring systems are: 1) weighting system; 2) laser triangulation distance system; and imaging system.
Weighting System
The weighting system measures the mass of powder being spread by the SpreadStation over time. The weighting system uses load cells to measure the powder mass and 24 bit A to D converters to digitize the load cell readings.
Weighting System Data:
Spreading Efficiency: The spreading efficiency is the ratio of the spreading density to the material density. A spreading efficiency of 100% means the spread layer is equivalent to a solid layer of material while a spreading efficiency of 0% means there is no powder in the layer.
Spreading Density: The density of the layer of the powder, units grams/cm3
Spreading Rate: The mass of powder exiting the spreader over time, units grams/cm
Spreading Uniformity: The uniformity of the layer density from the start of the test to the end of the test, units %
Laser Triangulation System
The laser triangulation system measures the thickness of the powder layer created by the SpreadStation.
Laser Triangulation System Data:
Layer thickness: The thickness of the powder layer measured over time, units micrometers
Layer Thickness Uniformity: The unformity of the powder layer thickness, units %
Imaging System:
The imaging system consists of digital cameras and LED lighting that collect images of the powder layers created by the SpreadStation. Image analysis software is then used to extract information about the layer quality.
Imaging System Data:
Area Coverage: The area coverage is the ratio of the area in the image covered by powder to the total area of the image, units %
Channel Detection: The image analysis software determines if there are any channels is the powder layer and if so the width of the channel, units % channels, width millimeters
Wave Detection: The image analysis software determines if there are any waves in the powder layer and their widths, units % waves, width millimeters