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of the first SINGLE image you encounter, call this speed “A”. Continue
decreasing the flash rate until you encounter a second SINGLE image. Note
this speed as “B”. Continue decreasing the speed until you reach a third
SINGLE image at speed “C”.
For a two point calculation the actual speed is given by:
RPM = AB/(A-B)
For a three point calculation:
RPM = 2XY(X+Y)/(X-Y)
2 where
X = (A-B) and Y = (B-C)
If a Remote Optical Sensor or Magnetic Sensor is used to sense one pulse per
revolution (External mode), the readout will display directly in RPM (FPM)
without any adjustment required.
In instances when you can shut down the device and install a piece of reflective
tape, then an optical tachometer is easier to use for RPM measurement.
Stroboscopes must be used when you can’t shut down the device. The human
eye is not easily tricked into seeing a stopped image by a stroboscope when
the flash rate is slower than 300 FPM. Therefore, stroboscopes are just about
impossible to use below 300 FPM for inspection or to measure RPM.
7.0 BATTERIES
The Nova-Strobe LED is fitted with rechargeable NiMH (Nickel Metal
Hydride) batteries. These batteries contain fewer toxic metals than NiCd
(Nickel Cadmium) and are currently classified “environmentally friendly”.
They also have 30% more capacity than NiCd batteries of the same size.
Like NiCds, NiMH batteries are prone to self-discharge - 10 to 15% of charge
is lost in the first 24 hours then continues at a rate of 0.5 to 1% per day. For
maximum performance, charge the batteries just prior to use.