Therefore, the user may accurately set {HEAD ~ the motion threshold} using {TAIL ~ the current level} as a reference, as shown in the drawings of the invention 
using
Therefore , the user may accurately set { HEAD ~ the motion threshold } using { TAIL ~ the current level } as a reference , as shown in the drawings of the invention
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH