Apple has refused to provide the calibration tool for the sleep sensor to independent repair people.
A German repairman has beaten Apple and developed a calibration tool.
That's cool but I thought they were kind of going to go more in to how they figured out the calibration works in order to build the tool to do it and what the device is doing. This is more like a how use the tool demo which isn't of as much interest since I don't run a repair shop and will unlikely repair a laptop myself.