Breitling BENTLEY MOTORS Manual De Instrucciones página 18

2.2 Other uses
Variable tachometric scales can be used for performing other calculations: multi -
plications, divisions, rules of three, hourly production rates, hourly consumption
or flow rates, heartbeats/minute (pulsometer), etc.
Multiplication: to multiply 3 x 18, place the figure 18 on the
fixed scale or the mobile scale opposite the figure 3. t he
HOURS mark on the fixed scale and figure 1 on the mobile
disc both indicate the result, which is 54.
Division: division works in the opposite way to the pre-
vious example. t o divide 54 by 2, one need only place the
figure 54 opposite the HOURS mark on the fixed scale or
figure 1 on the mobile disc. t he result is read off opposite
figure 2 on one or other of the scales. t his single operation
produces a complete division table of the figure 54:
54 : 2 = 27
54 : 3 = 18
54 : 18 = 3, etc.
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Rule of three: both scales enable one to perform a multiplica -
tion and then a division in just one operation. For example,
to determine the price of 6 meters of cable, if 1.5 meters
costs £ 9, one places the number 9 opposite the figure 6. t he
result is shown opposite the figure 1.5; in this case £ 36.
Hourly production or consumption rate: measuring a produc -
tion rate or an hourly consumption rate follows the same
principle as the measurement of an average speed. For
example, if a machine produces 15 units in 45 seconds,
what is its hourly production?
Solution: place the figure 15 (the quantity produced) on the
SECONDS mark on the fixed scale, then read off the result
opposite figure 45 (interval measured); in this case 1,200 units
per hour.
Pulsometer: the pulsometer enables fast calculation of pulse
rate. For example, if 27 beats are measured over a 24-second
period, one need only place the figure 27 (number of heart -
beats) opposite the MINUTES marker, and then read off the
result opposite figure 24 (length of observation); in this
case 67 beats per minute.
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