dynamometers

Dynamometers are devices that measure force, torque, or power by applying a controlled load to a test object and recording the resulting motion and resistance. They are widely used in engineering, research, and industry to quantify the output and efficiency of engines, motors, and drivetrains.

There are several common configurations. Absorption, or brake, dynamometers apply a configurable braking load to the rotating shaft and dissipate energy as heat. Inertia, or flywheel, dynamometers use the inertia of a flywheel to test performance under transient conditions, often with a control system that imposes a prescribed acceleration or deceleration. Hydraulic and electric (or magnetic) dynamometers convert the mechanical load into hydraulic fluid or electrical energy that can be controlled, measured, and often returned to the test system.

Engine dynamometers test a stand-alone engine by coupling to the crankshaft, allowing measurement of output under controlled conditions and without the vehicle. Chassis dynamometers test complete vehicles by applying load to the drive wheels, simulating road resistance while the vehicle is stationary or moving.

Measurements focus on torque and rotational speed, from which power is calculated using the relation Power = Torque × angular speed. Torque may be measured directly with torque sensors or inferred from force and lever arm measurements. Output power is typically reported in kilowatts or horsepower; efficiency and fuel or energy use can also be assessed by comparing output to input energy.

Calibration and maintenance are essential for accuracy. Dynamometers require periodic calibration to traceable standards, reliable sensors, proper lubrication, cooling, and safe operating procedures to minimize wear and measurement error.