Have you felt the floor vibrate due to a loud music from a speaker? Try holding a speaker while a song is playing. Sound is produced because of these vibrations. Depending on the vibration, the sound can be too loud or the opposite. To know how much sound is needed, measurement of the vibration is essential.
Vibrations are considered mechanical energies that cannot be quantified unless converted to a proportional electrical energy that can be measured. For this reason, you need an instrument that can do this conversion for you.
There are several instruments and tools that can be used to measure vibration. Get to know some of them and how they can be used so you can take the measurement yourself. Read the information below for guidance.
Measure vibration using accelerometers:
An accelerometer is a device that measures the proper acceleration relative to freefall or acceleration of people or objects. The electrical signals coming out of the accelerometer can also indicate the amount of vibration.
For this experiment, get a moist mass and load it on a spring. Vibration is then sent from the springs into the accelerometer. The spring would continue to vibrate and displace the moist mass. Measure the amount of displacement, as this is the amount of acceleration of the vibration.
Accelerometers are smaller in size and more lightweight compared to velocity pickups. Also, they are more sensitive in picking up frequencies without the need to direct contact to the vibrating surface.
Measure vibration using velocity pickups:
A velocity pickup is popular vibration transducer. Its sensitivity varies depending on the manufacturer, but all of them are able to serve the purpose of measuring vibration. An added plus for using velocity pickups is the cost. These are far less expensive than other sensors.
Velocity pickups can read vibration on rotating pieces of machineries. These machines generate vibration, and the job of the velocity pickup is to generate the same amount of electric signal as the vibration. As the machine is rotating constantly, the vibration reading will repeat its pattern over a period of time.
Compared to an accelerometer, a velocity pickup needs to be directly attached to the machine to get the vibration frequencies. Make sure it is securely attached on the surface before conducting the reading. You can use magnets or silicon grease for this. When using magnets, however, be warned that the reading may not be as accurate. Magnetic mounts have their own spring-like qualities that when used can also generate vibrations to the surface. This will add up to the velocity pickup’s reading.
Though accelerometers are more lightweight, the extra weight of the velocity pickup makes it more durable and sturdy, enabling it to withstand harsh environment. For this reason, it is more widely used in the industrial field compared to accelerometers.
There is no need for you to go far to conduct your experiment. Simple tools at home can cause vibration that you can measure.
As with the instruments for measurement, the heavy-duty ones can be costly. Check with your school if they can lend you one to experimentation purposes.