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A dynamometer determines the POWER an engine produces by applying a load to
the engine output shaft by means of a water brake, a generator, an eddy-current
absorber, or any other controllable device capable of absorbing power. The
dynamometer control system causes the absorber to exactly match the amount of
torque the engine is producing at that instant, then measures that TORQUE as
well as the RPM of the engine shaft, and from those two measurements, it
calculates observed power. Then it applies various factors (air temperature,
barometric pressure, relative humidity) in order to correct the observed power
to the value it would have been if it had been measured at standard atmospheric
conditions (corrected power).
A dynamometer, also known as a dyno, is a machine used to measure RPM and torque
from which power produced by an engine.
There are two types of dynos: one that is bolted directly to an engine, known
as an engine dyno, or a dyno that can measure power and torque without removing
the engine from the frame of the vehicle known as a chassis dyno.
Engine Dynamometer (Dyno)
An engine dynamometer measures power and torque directly from the engine’s
crankshaft (or flywheel), when the engine is removed from the vehicle. These
dynos do not account for power losses in the drivetrain, such as the gearbox,
transmission or differential.
Chassis Dynamometer (Dyno)
A chassis dynamometer measures power from the engine through at the wheels. The
car is pulled up on the dyno rollers which the car then turns and the output is
measured. Chassis dynos can be installed in the ground, above ground and on
trailers so they can be transported.
Due to frictional and mechanical losses in the various drivetrain components,
the measured horsepower is usually 15-20 percent less than the actual horsepower
measured at the crankshaft or flywheel on an engine dynamometer.
A dynamometer works by absorbing the power developed by the test engine and
measuring the torque required to do so. Power is then calculated from the torque
and RPM figures and proportioned to a standard horsepower
A dynamometer only measures torque and RPM and power is calculated from those
measurements.
Category:
Type: Ailments
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