Linear velocity sensors measure the linear velocity of an object using either contact or noncontact techniques.  Important performance specifications to consider when searching for linear velocity sensors include maximum velocity, maximum measurement range, accuracy, and operating temperature.  The maximum velocity represents the maximum linear velocity that can be measured.  The maximum measurement range is the maximum range or distance at which the sensor can measure speed.  The measurement accuracy of the device, measured in ±% full scale.  Accuracy can have somewhat varying definitions, and can include nonlinearity, hysteresis, and measurement resolution.  The operating temperature is the range of temperatures over which the device must function.