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the target is. Optimal setting to stop motion is 1.8 to 3.6°. The number of
degrees is a proportional amount and remains constant as the flash rate
increases or decreases. The strobe automatically calculates how wide the
pulse width should be at different flash rates to keep the blur constant – the
faster the flash rate the narrower the pulse width. The pulse width equals:
(setting in degrees/360) x (1/flash rate in Hz).
Thus the blur remains constant no matter what the flash rate*.
5.3 Brightness in Pulse Duration
The second method is to adjust the flash pulse width to a fixed number of
microseconds. Here the user sets the flash pulse width in microseconds
not degrees. As the flash rate increases the pulse width stays the same and
the image will get brighter and more blurred as the flash width remains
constant*. The degree of rotation visible changes to keep the pulse width
of the flash constant*.
*
Note:
There are two limits maintained by the strobe – the pulse can
never be greater than 3000 µs nor can it exceed 14° of rotation. The strobe
automatically adjusts these values as the flash rate is increased or decreased
to maintain these limits at all times. For example - at a flash rate of 600
flashes per minute 14° of blur represents a flash pulse width of 3800 µsec.
The Strobe will limit this value to 3000 µsec or 10.8° of rotation (blur).
6.0 USING THE STROBOSCOPE TO
MEASURE RPM
The primary use for a stroboscope is to stop motion for diagnostic inspection
purposes. However the stroboscope can be used to measure speed (in RPM
/ RPS). In order to do this several factors need to be considered. First, the
object being measured should be visible for all 360° of rotation (e.g. The
end of a shaft). Second, the object should have some unique part on it, like a