Be sure to watch Big Clive's video that's linked in the article. It's amazing how cheap digital calipers have gotten, and how accurate they are at that price. They probably use a 4-bit MCU or an ASIC to do the calculations and output the data --- both to the screen, and an often-hidden serial port. The use of a non-absolute encoding leading to drift, and the higher standby power consumption which was distinctive of the infamous battery-eating Mitutoyo clones, seems to have been largely solved within the past few years. There are even solar models available for not much more.