Obviously, you'd wonder why the iPhone wouldn't measure signal in a more linear fashion, where the decibel value for each bar is equal.
很明显，你可能很想知道，为什么iPhone不用更线性的方式来测量接收强度，每格表示的分贝值相同呢？
3
It is accurate to within 0.03mm. The same sensor is used on a boat to shine a beam off the tiller bar, using the reflection to measure the Angle of the rudder.