4. The chronograph second hand is compared to the
tachymeter markings to determine the target's speed.
SLIDE-RULE BEZEL FUNCTION
The slide rule function of the top ring operates by rotating
the outer ring. The inner ring does not move. The outer
ring is always related to "distance" or "speed", or any
data that varies with time. The inner ring only notes units
of time.
Outer Ring
On the outer ring, the figure "10" represents factors or
multiples of 10, such as 0.1, 1.0, 10, or 100.
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