Monarch Instrument Nova-Strobe BBL - Manual (Page 5)

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Figure 1 LED Strobe
Control Panel
1.0 OVERVIEW
The Nova-Strobe Basic BBL LED
(Light Emitting Diode) is a rugged
portable battery powered LED
Stroboscopes used for inspection
and to stop motion to determine
the speed of rotating objects. The
unit has a pistol grip with lockable
trigger switch and wrist strap for
comfortable hand held operation
or it may be mounted on a tripod
using the integral ¼ -20 UNC
thread at the base of the handle.
The Basic LED Strobe has a two
line backlit alpha-numeric liquid
crystal display (LCD) and a 4 key keypad that enables the user to control
the operation of the unit. Most of the icons in the LCD display are not
used.
1.1 Brightness
GLOSSARY:
LED – Light Emitting Diode
msec – millisecond = 1/1,000 of a second
µsec – microsecond = 1/1,000,000 of a second
° = degree. One rotation = 360°
The strobe’s brightness depends on how wide the LED flash pulse is;
the wider the pulse, the brighter the visual output from the LEDs. Since
the strobe is primarily used on reciprocating or rotating targets there is
a downside to the wider flashes. All strobes work by giving short bursts
of light (the pulse width) at a rapid repetition rate (the flash rate). Strobes
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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)
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.
5.0 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.
When not in use, the batteries should be charged at least every three months,
otherwise the battery capacity will be reduced or the batteries may become
unusable.
Charge the batteries before use and allow 3-5 cycles of charging and
discharging for batteries to reach full capacity.