Stroboscopes, commonly referred to as strobes, use a flash lamp—generally xenon or LED— driven by an oscillator to inspect or measure the rotational speed of spinning objects. The oscillator activates the lamp at a steady state which can be set at rates from a flash every few seconds to hundreds of flashes per second. The flashing light creates the perception of stop-motion which is ideal for diagnostic inspections of moving machinery and can also be used as a measuring instrument for determining cyclic speed as measured in rotations per minute (RPM).
The flashing light of the strobe creates an optical illusion known as aliasing. As the strobe flashes it provides intermittent glimpses of the moving target. When the flash rate of the stroboscope matches the rotational rate of the target, each flash illuminates the target at the same position in its rotational cycle creating the perception that the object is stationary. Once this point is reached the flash rate can increased or decreased to make it appear as if the object is rotating forward or backwards—the speed of which is dependent upon how much the flash rate of the stroboscope varies from the rotational rate of the target.
The ability to visually “stop and start” a spinning piece of machinery or adjust its rotational speed and direction is an important inspection and troubleshooting tool. Technicians can identify damage to gears, shafts, pulleys, and belts without having to stop the machinery. Additionally, any wobbles or alignment problems can be quickly noticed before the problem becomes severe.
Though the ability of a stroboscope to visually stop the motion of a piece of machinery for inspection is the primary use of the instrument, it is also quite useful as a tool capable of measuring rotational speed. Measuring rotational speed involves matching the flash rate of the strobe to the rotational rate of the equipment being tested. Some sort of reference mark, such as reflective tape, makes this easier. Once the rates match, the stroboscope can convert the number of flashes per second to RPM.
Applications for Stroboscopes:
Stroboscopes are valuable tools for inspecting and measuring the spinning speed of rotating equipment. This is important for a wide range of equipment including:
- Centrifuges
- Saw blades
- Grinders
- Elevators/escalators
- Engines
- Motors
- Conveyor belts
- Fans
- Propellers
Things to Consider When Selecting a Stroboscope:
- Does the application involve rotational analysis or only rotational speed measurement?
- Is spot testing or permanent placement needed?
- What is the maximum RPM the instrument will measure?
- What level of accuracy is required?
- Is contact or non-contact measurement preferred?
- What price range is most attractive?
If you have any questions regarding stroboscopes please don't hesitate to speak with one of our engineers by e-mailing us at sales@instrumart.com or calling 1-800-884-4967.
