Speed sensors

thumb|An animation of an Speedometer#Electronic|electronic [[Aston Martin speedometer's self-test routine, showing how an analogue speedometer hand may indicate the vehicle's speed]] thumb|A Ford Motor Company|Ford speedometer, showing both mph (outer) and km/h (inner), as well as an [[odometer in miles]] thumb|A digital, LCD speedometer in a [[Honda Insight]]

pressure measurement instrument used to measure fluid flow velocity

thumb|300px|A tachometer that can indicate up to 7000 revolutions per minute|RPM (left)

instrument used in an aircraft to display the craft's airspeed, typically in knots, to the pilot

thumb|right|Illustration showing the face of a Machmeter reading a Mach number of 0.83

system of pressure-sensitive instruments that is most often used in aviation

A linear or rotary electromechanical device that has two electrical outputs, A and B, which issue pulses when the device is moved.

also known as floating cellular data

atom-based relative location determining system