Breitling BENTLEY MOTORS Manual De Instrucciones página 16

Example 2: if it takes 36 seconds to cover one kilo -
meter or one mile, the average speed is 100 km/h
or 100 mph respectively.
n .B. t his tachometric scale, used in conjunction
with the 30-seconds chronograph function, is espe -
cially suited to measuring high speeds ranging
between 95 km/h (or mph) and 320 km/h (or mph).
Consequently, the observation time is limited to
between 11 and 38 seconds.
2. V
ARIABLE TACHOMETER
t he variable tachometer enables one to determine an average speed whatever
the distance covered, the time elapsed or the speed reached. It is however an
approximate measurement device.
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t he variable tachometer is composed of a fixed scale (a) and a mobile scale or
disc (b). t he fixed scale is read off clockwise, and the mobile disc in the oppo-
site direction. t he graduations between two numbers represent tenths of units.
t o read off a result, the decimal point must be placed correctly. For example,
the figure 3.2 may represent 0.32, 3.2, 32, 320, etc. t he fixed scale comprises
three reference marks:
Se COn DS (1) on the figure 3.6 (one hour equals 3,600 seconds);
G
MIn Ut e S (2) on the figure 6 (one hour equals 60 minutes);
G
HOUr S (3) on the figure 1 (one hour is the base unit for all calculations).
G
2
1 3
a
(a) Fixed scale
(b) Mobile scale (disc)
b
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