There may be a range of possible outcomes associated with an event depending on the types of dynamometer pdf of view, historical distance or relevance. Reaching no result can mean that actions are inefficient, ineffective, meaningless or flawed. This page was last edited on 7 September 2017, at 09:47.
Unsourced material may be challenged and removed. Early hydraulic dynamometer, with dead-weight torque measurement. In addition to being used to determine the torque or power characteristics of a machine under test, dynamometers are employed in a number of other roles. They are also used to measure grip strength in patients where compromise of the cervical nerve roots or peripheral nerves is suspected.
Typically the force applied to a lever or through a cable is measured and then converted to a moment of force by multiplying by the perpendicular distance from the force to the axis of the level. The dynamometer must be able to operate at any speed and load to any level of torque that the test requires. Absorbing dynamometers are not to be confused with “inertia” dynamometers, which calculate power solely by measuring power required to accelerate a known mass drive roller and provide no variable load to the prime mover. An absorption dynamometer is usually equipped with some means of measuring the operating torque and speed.
This power absorbed by the dynamometer is then converted into heat, which generally dissipates into the ambient air or transfers to cooling water that dissipates into the air. AC inverter – can feed AC power back into the commercial electrical power grid. Absorption dynamometers can be equipped with two types of control systems to provide different main test types. The dynamometer has a “braking” torque regulator – the power absorption unit is configured to provide a set braking force torque load, while the prime mover is configured to operate at whatever throttle opening, fuel delivery rate, or any other variable it is desired to test. The prime mover is then allowed to accelerate the engine through the desired speed or RPM range. Constant force test routines require the PAU to be set slightly torque deficient as referenced to prime mover output to allow some rate of acceleration. Power is calculated based on rotational speed x torque x constant.
The constant varies depending on the units used. The PAU braking load applied to the prime mover can be manually controlled or determined by a computer. Most systems employ eddy current, oil hydraulic, or DC motor produced loads because of their linear and quick load change abilities. Power is calculated based on rotational speed x torque x constant, with the constant varying with the output unit desired and the input units used. It must be able to drive the equipment at any speed and develop any level of torque that the test requires. In common usage, AC or DC motors are used to drive the equipment or “load” device.