A dynamometer is a device for measuring force, torque, and power. A dynamometer, or “dyno,” is a device that measures the torque and rotational speed (RPM) of an engine, motor, or other rotating prime mover at the same time, allowing the instantaneous power to be calculated and typically shown as kW or bhp by the dynamometer itself. It is widely used in industries such as engineering, automotive, aerospace, and sports science to test and evaluate the performance of engines, motors, vehicles, and other mechanical systems.

Dynamometers are used for a variety of purposes other than determining torque or power characteristics of a machine under test. Dynamometers are used in standard emissions testing cycles, such as those prescribed by the United States Environmental Protection Agency, to replicate road loading of either the engine (with an engine dynamometer) or the entire powertrain (with a chassis dynamometer).

Aside from simple power and torque measurements, dynamometers can be utilized as part of a testbed for a range of engine development activities, including engine management controller calibration, comprehensive combustion behavior investigations, and tribology.

Dynamometers come in different types depending on their application:

  • Engine Dynamometer: Also known as an engine dyno, this type of dynamometer is used to measure the power output, torque, and other performance parameters of internal combustion engines. It allows engineers to test engines under controlled conditions without the need for a vehicle.
  • Chassis Dynamometer: This dynamometer measures the performance of a vehicle as a whole. The vehicle is placed on rollers, and the dynamometer measures the power output at the wheels. Chassis dynamometers are commonly used for emissions testing, tuning, and performance evaluation of cars, motorcycles, and other vehicles.
  • Brake Dynamometer: Also called a absorption or load dynamometer, it measures the torque output of a motor or engine. It typically consists of a brake mechanism that applies a load to the motor or engine being tested. The amount of torque required to overcome this load is measured, allowing for the determination of the motor or engine’s torque characteristics.
  • Towing Dynamometer: This type of dynamometer is used to assess the performance of vehicles such as trucks, trailers, and recreational vehicles when towing. It replicates real-world towing scenarios to evaluate vehicle performance, fuel consumption, and other parameters.

Dynamometers are essential for research and development, quality control, performance tweaking, and troubleshooting of diverse mechanical systems. They give essential data that engineers and researchers can utilize to enhance designs, increase economy, and maintain machine and vehicle reliability.