Frequently Asked Questions About Dynamometers

A dynamometer, or dyno for short, refers to a device that specializes in measuring force, power, and torque. These devices are commonly used for testing the power of a motor or any other type of force. One example is a hand-held medical device that can measure the strength of a persons grip for the diagnosis or rehabilitation of certain conditions.

What are the main types of dynos?

These devices vary widely in their complexity depending on what you are trying to measure. Complex machines require more complex measurement devices.

  • Spring dynamometer: This device consists of a simple spring, which measures a pulling force.
  • Driving dynamometer: This device is essentially just an ordinary electric motor that can measure how much power or torque you need to produce in complex machinery.
  • Absorption dynamometer: This type of device acts as a variable load that an engine, motor, or any other type of force drives. It essentially absorbs power to measure how much torque or force it actually has.
  • Universal types: This is a combination of a driving and an absorption device.
How does a dynamometer measure power or torque?

Apart from the simple spring types, the following technologies are commonly deployed in the more complex dynos.

  • Eddy current: An eddy current is a loop of an electrical current. It is produced by an electrically conductive core, shaft, or disc moving across a magnetic field. The currents generate force, which can be measured.
  • Powder: This is similar to an eddy current device, except a fine magnetic powder is constantly being brought together and then broken apart during rotation to measure force.
  • Hydraulic: This type of device measures the hydraulic pressure to gauge the force or power of an object.
  • Hysteresis: Torque is generated in proportion to the magnetic current of a rotor.
How does a dynamometer work with an engine?

One of the most common uses of a dyno is to measure the power produced by an engine of a vehicle for the purpose of testing. The device can be attached to the chassis and thus measure the force delivered by the powertrain of the vehicle, or it can be attached to the engine directly. Both engine and chassis types may be used together to measure the power transfer at different points within the vehicle. For example, if there is a large disparity between the chassis and engine, then you can tell where inefficiencies in the design lay.