Operation Manual

108
109
TACHYMETER FUNCTION
(not all models)
The tachymeter will only determine speeds greater than
60 units per hour using this method; slower speeds can
be measured by decreasing the unit of measurement.
The function performed by a tachymeter is independent
of the unit of distance (e.g. statute miles, nautical miles,
kilometers, meters etc.) as long as the same unit of length
is used for all calculations.
1. Determine the start and finish markers for your
pre-determined distance.
2. Start the chronograph once the target for speed
measurement passes the start marker.
3. Stop the chronograph once the target for speed
measurement passes the finish marker.
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.