To. TEST the stroboscope, proceed as follows:
a. Allow the instrument to warm up for about 10 minutes.
b. Refer to SELF TEST table in the instrument cover or to Table
2-1 for the HIGH CAL and LOW CAL RPM dial settings indicated for the
power -line frequency being used. Turn the range switch to the corres -
pending range required to make these settings.
c. Set the RPM dial to the exact HIGH CAL RPM dial setting called
for in the SELF TEST table.
d. Adjust the HIGH CAL screwdriver control until the on -off pattern
of the CAL neon indicator lamp stops, or nearly stops (refer to para -
e. Set the RPM dial at the exact LOW CA L RPM dial setting indicated
in the SELF TEST table and adjust the LOW CA L screwdriver control until
the on-off pattern of the CAL neon indicator lamp stops, or nearly stops.
f. Return the RPM dial to the HIGH CAL RPM setting. If the CAL
indicator lamp blinks on and off too rapidly, repeat steps d, e, and f.
This step is usually not necessary unless the LOW CAL adjustment was
g. The RPM dial is now calibrated to within 1% on all scales.
SELF TEST DATA
RPM Dial Settings
LOW CAL .
2.7.2 SELF TEST ERROR.
The action of the CAL indicator lamp is used to determine when
either of the HIGH CAL or LOW CAL adjustments are properly set. Ex -
tremely slow on-off action of the lamp indicates the calibration setting
is very close to the line frequency and generlly accurate enough for
most speed measurements. If desired, the SELF TEST error can be
calculated as follows:
a. First, observe the period (in seconds) required for the CAL
indicator lamp to complete one full cycle on to off to on again, for
Then, calculate the SELF TEST error by:
= rpm error
line frequency (c/s) xT