Editing Dynamometer (section)

==Types of dynamometer systems==
[[Image:boxsterdyno.png|right|thumb|300px|Dyno graph 1]]
[[Image:dynograph96.jpg|right|thumb|300px|Dyno graph 2]]

A 'brake' dynamometer applies variable load on the prime mover (PM) and measures the PM's ability to move or hold the RPM as related to the "braking force" applied. It is usually connected to a [[computer]] that records applied braking torque and calculates engine power output based on information from a "load cell" or "strain gauge" and a speed sensor.

An 'inertia' dynamometer provides a fixed inertial mass load, calculates the power required to accelerate that fixed and known mass, and uses a computer to record RPM and acceleration rate to calculate torque. The engine is generally tested from somewhat above idle to its maximum RPM and the output is measured and plotted on a [[Graph of a function|graph]].

A 'motoring' dynamometer provides the features of a brake dyno system, but in addition, can "power" (usually with an AC or DC motor) the PM and allow testing of very small power outputs (for example, duplicating speeds and loads that are experienced when operating a vehicle traveling downhill or during on/off throttle operations).