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.
Inner Ring
On the inner ring, “MPH” (mile per hour) refers to “speed index”. This index is used to calculate the speed involving any data per hour. On the inner ring, “STAT” (statute miles) and “NAUT” (nautical miles) are for conversion of distance units.
OUTER RING
INNER RING
90 | 91 |
