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When using a strobe light to determine the RPM of a rotating item and you read 1000 and 2000 how do you know which is correct?


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2007-09-04 16:06:43
2007-09-04 16:06:43

Start from the lowest setting on the strobe, and then work your way up till you find the highest setting that freezes the rotating item. This will hold for a single blade. Lower strobe settings (lower rpms) may also look correct, but you're actually catching the item at half the true rpm. The item will appear to be stopping after 1 revolution, but you're watching it after 2 revolutions every time the strobe flashes. With a two bladed propeller, you run into a similar problem, except that running the strobe twice as fast can give misleading results. It is helpful to make an identifying mark on one blade that can be easily seen when the strobe is running. Then find the highest rpm where that marking stays in the same spot. This will assure you that you aren't counting half rpm, and that you aren't counting twice rpm by watching the other blade move to the same spot.

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2. A strobe light works by illuminating an object with a very brief flash of light. If this flash of light is repeated at the same rate as an object is rotating, then the rotating object will appear to be stationary. The flash of light is produced by a flash tube similar to that on a modern camera, but one capable of having a very short pulse of light, and at very great intensity. The modern Strobe light was invented by Edgerton, and he went on to invent Side Scan Sonar, a powerful technique for viewing the seabed. The primitive origin of the strobe light can be seen as a slit in a cardboard disk, which is rotation at the same speed as the object is rotating. The technique is not limited to rotating machinery - any repetitive motion may be studied. And with single flashes, a short-lived phenomena may be captured on film.

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I believe dr. Harold edgerton invented the strobe light.

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Answer= 1.A Strobe is a light that flashes on and off continuously.

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Well to determine the cost of a strobe light you would have to figure out how many lights you would like to have as well as the quality of the lighting.I have seen them range from maybe $6.99 to $20.99 or higher depending on what you want.

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Assuming there is one reference mark on the rotating object to start with, a strobe tuned to exactly one half times RPM will show only one reference mark, i.e. one every other revolution.


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