Accuracy evaluation of a lower-cost and four higher-cost laser scanners

The RMSEs in scanning the gage block were 2 to 52 µm lower than the overall errors stated by the manufacturers. The repeatability in scanning the bovine femur 10 times was significantly worse than that in scanning the gage block 10 times. The precision of the lower-cost laser scanner was comparable to that of the higher-cost laser scanners, but the bias was an order of magnitude greater. The contributions of this study are that 1) the overall errors stated by the manufacturers are an upper bound when simple geometric objects like a gage block are scanned, 2) the repeatability is worse on average three times when scanning a complex freeform surface compared to scanning the gage block, and 3) the main difference between the lower-cost and the higher-cost laser scanners is the bias.