The "NOT do that thing" is the questionable part, lots of devices that measure things can claim to do so when they aren't "accurate". The difference is how inac

The "NOT do that thing" is the questionable part, lots of devices that measure things can claim to do so when they aren't "accurate". The difference is how inaccurate is the device and is the margin of error something that should be communicated. The classic example are scales, you can buy scales and weigh yourself on them and they might not be 100% accurate. But you can still sell a product that claims you can weigh yourself. Should we require standards that require companies to provide a +/- variance against exact measurements? Some products do such as power meters. If a product is outside of a particular variance then could we call those scam products?