public final double sampleCount(){
  long lastAcquireCount=_lastAcquireCount;
  _lastAcquireCount=_acquireCount.get();
  return _lastAcquireCount - lastAcquireCount;
}

public final double sampleCount ( ) { long lastAcquireCount = _lastAcquireCount ; _lastAcquireCount = _acquireCount . get ( ) ; return _lastAcquireCount - lastAcquireCount ; }
return the probe ' s next sample .
