The history and the myth surrounding dynamometers
Dynamometer is a measuring component in a car’s engine that is meant for measuring the power of the car’s engine. This interesting engineering device has a long history. The precursor of modern day dynamometer is a device called the de Prony brake. Gaspard de Prony invented it in 1821. A Worcester based leading UK manufacturer of vehicle dynamometers called Froude Hofmann, says that the pioneer of the hydraulic dynamometer is William Froude. He invented the first effective hydraulic dynamometer in the year 1877. According to the firm, the first business oriented dynamometer was made in 1881. A German company in 1921 has the record of manufacturing the first effective car dynamometer that comes closest to the present generation devices.
Another landmark in the history of dynamometer was achieved in the year 1931. Anthony Winther and Martin invented the eddy current dynamometer in this year. During those times, the trend in the car industry was to use DC Motor or generator dynamometers. Winther later founded a corporation named Dynamatic Corporation that produced dynamometers till 2002. For the years 1946 to 1995, it was under the ownership of Eaton Corporation. The company was taken over by Dyne systems in 2002.
There are some myths and misconceptions regarding the use and purposes of a dynamometer. Though all engineers agree in unison that it is a vital engineering device yet there are many misconceptions that are surrounding it. The power of a vehicle is often benchmarked by parameters like torque figures and Horsepower. While these are accepted they are not the only factors deciding a car engine’s power output. A car engine and a dynamometers engine are not totally similar.
Some people think using dynamometer tests can cause damages to the engine. This however is not true. As a matter of fact, a brake dynamometer delivers a load in Steady state mode equaling the power an engine is creating at certain rpm point. For example, if the engine generates 200 BHP at 5000-rpm then the dynamometer’s power absorber or brake will give equal load, thus keeping the rpm figures same. If the road is ok, the dynamometer should not cause any problem. Therefore it is nothing but a myth that dynamometer test can harm your vehicle.
Nevertheless it should be kept in mind that the worries over the connection of engine damage and Dynamometer testing do have some grounds. In certain traditional water brake style dynamometers water filling and draining is used to regulate the load on the device. The water is refilled and drained to prevent it from boiling. As a result of this, the computer faces difficulties to stabilize the outflow and inflow rates. Here it is not the amount of load that acts truant, the time required to stabilize the load becomes the headache. But this water brakes are still employed in big boats and vehicles where the light weight and the small size plays a decisive role.