About a function and performance
- Q12
- How is the slide rule used?
- A12
- Using the slide rule
A. General Calculation Functions
1) Multiplication
Example: 12 × 15
Operation: Align “12” on the outer scale with “10” on the inner scale.
Then, “15” on the inner scale corresponds to “18” on the outer scale.
Take into account the position of the decimal point and add one zero
to obtain 180. Note that with the scales of this watch, the position of
the decimal point cannot be obtained.
2) Division
Example: 300 / 15
Operation: Align “30” on the outer scale with “15” on the inner scale.
Then, “10” on the inner scale corresponds to “20” on the outer scale.
Take into account the position of the decimal point to obtain 20.
3) Reading Ratios
Example: 50 / 20 = 30 / x
Operation: Align “50” on the outer scale with “20” on the inner scale.
Then, “30” on the outer scale corresponds to “12” on the inner scale.
At this point, the proportion for every value on the inner and outer
scales is “50:20”.
4) Determining Square Root
Example: Square root of 169
Operation: Turn the outer scale slowly and find a value that corresponds
to both “16.9” on the outer scale and “10” on the inner scale.
In this example, “16.9” on the outer scale corresponds to “13” on the
inner scale, and “10” on the inner scale corresponds to “13” on the
outer scale. Thus, the answer is 13.
B. Navigation Calculator for motor sports
1) Time required
Example: Obtain the time required 55 kilometers per hour for 330 kilometers.
Operation: Align “55” on the outer scale with the SPEED INDEX “▲” on
the inner scale. Then, “33” on the outer scale corresponds to “6:00” on
the inner scale (time scale). Thus, the time required is 6 hours.
* It is calculable also as mile instead of kilometer.
2) Speed
Example: Obtain the kilometers per hour for 120 kilometers with a time
of 1 hour and 30 minutes.
Operation: Align “12” on the outer scale with “1:30” on the inner scale
(time scale). Then, the SPEED INDEX “▲” on the inner scale
corresponds to “80” on the outer scale. Thus, the speed is 80 kilometers
per hour.
3) Mileage
Example: Obtain the mileage when the speed is 40 kilometers per hour
and the running time is 1 hour and 30 minutes.
Operation: Align “40” on the outer scale with the SPEED INDEX “▲” on
the inner scale. Then, “1:30” on the inner scale (time scale) corresponds
to “60” on the outer scale. Thus, the mileage is 60 kilometers.
4) Rate of fuel consumption
Example: Obtain the rate of fuel consumption (liters / hour) when the
running time is 5 hours and the fuel consumption is 35 liters.
Operation: Align “35” on the outer scale with “5:00” on the inner scale
(time scale). Then, the SPEED INDEX “▲” on the inner scale
corresponds to “70” on the outer scale. Thus, the fuel consumption is
7 liters per hour.
5) Fuel consumption
Example: Obtain the fuel consumption required for a running when the
rate of fuel consumption is 6 liters per hour and the running time is 5 hours.
Operation: Align “60” on the outer scale with the SPEED INDEX “▲” on
the inner scale. Then, “5:00” on the inner scale (time scale) corresponds
to “30” on the outer scale. Thus, the fuel consumption is 30 liters.
6) Estimated running time
Example: Obtain the estimated running time when the rate of fuel
consumption is 5 liters per hour and the running has 30 liters of fuel.
Operation: Align “50” on the outer scale with the SPEED INDEX “▲” on
the inner scale. Then, “30” on the outer scale corresponds to “6:00” on
the inner scale (time scale). Thus, the estimated running time is 6 hours.
C. Navigation Calculator for sky sports
1) Time required
Example: Obtain the time required for the fight of an aircraft at 160 knots
for 240 nautical miles.
Operation: Align “16” on the outer scale with the SPEED INDEX “▲” on
the inner scale. Then, “24” on the outer scale corresponds to “1:30” on
the inner scale (time scale). Thus, the time required for the flight is
1 hours and 30 minutes.
2) Speed
Example: Obtain the knots (air speed) for 250 nautical miles with a flight
time of 1 hour and 40 minutes.
Operation: Align “25” on the outer scale with “1:40” on the inner scale
(time scale). Then, the SPEED INDEX “▲” on the inner scale
corresponds to “15” on the outer scale. Thus, the air speed for the flight
is 150 knots.
3) Flight distance
Example: Obtain the air distance when the air speed is 180 knots and
the flight time is 40 minutes.
Operation: Align “18” on the outer scale with the SPEED INDEX “▲” on
the inner scale. Then, “40” on the inner scale corresponds to “12” on
the outer scale. Thus, the air distance of the flight is 120 nautical miles.
4) Rate of fuel consumption
Example: Obtain the rate of fuel consumption (gallons / hour) when the
flight time is 40 minutes and the fuel consumption is 140 gallons.
Operation: Align “14” on the outer scale with “40” on the inner scale.
Then, the SPEED INDEX “▲” on the inner scale corresponds to “21” on
the outer scale. Thus, the fuel consumption is 210 gallons per hour.
5) Fuel consumption
Example: Obtain the fuel consumption required for a flight when the rate
of fuel consumption is 240 gallons per hour and the flight time is 1 hours
and 40 minutes.
Operation: Align “24” on the outer scale with the SPEED INDEX “▲” on
the inner scale. Then, “1:40” on the inner scale (time scale) corresponds
to “40” on the outer scale. Thus, the fuel consumption is 400 gallons.
6) Estimated flight time
Example: Obtain the estimated flight time when the rate of fuel consumption
is 200 gallons per hour and the aircraft has 1400 gallons of fuel.
Operation: Align “20” on the outer scale with the SPEED INDEX “▲” on the
inner scale. Then, “14” on the outer scale corresponds to “7:00” on the
inner scale (time scale). Thus, the estimated flight time is 7 hours.
D. Conversion
1) Distance
Example: Convert 45 miles into nautical miles and kilometers.
Operation: Align “45” on the outer scale with STAT “▲” on the inner scale.
Then, NAUT “▲” on the inner scale corresponds to about “39” nautical
miles on the outer scale, and KM “▲” on the inner scale corresponds to
about “72” km on the outer scale.
2) Weight
Example: Convert 16.4 oil lbs. into
and liters.
Operation: Align “16.4” on the inner scale with OIL LBS “▲” on
the outer scale. Then, U.S. GAL “▲” on the outer scale
corresponds to about “2.2”
IMP. GAL “▲” on the outer scale corresponds to about“1.8” IMP.
gallons on the inner scale, and LITERS “▲” on the outer scale
corresponds to about “8.3” liters on the inner scale.
3) Volume
Example: Convert 13.1 fuel lbs. into
and liters.
Operation: Align “13.1” on the inner scale with FUEL LBS “▲” on
the outer scale. Then, U.S. GAL “▲” on the outer scale
corresponds to about “2.2”
IMP. GAL “▲” on the outer scale corresponds to about “1.8” IMP.
gallons on the inner scale, and LITERS “▲” on the outer scale
corresponds to about “8.3” liters on the inner scale.
4) Fuel
Example: Convert 16.8
Operation: Align “16.8” on the inner scale with U.S. GAL “▲” on the
outer scale. Then, IMP. GAL “▲” on the outer scale corresponds to
about “14” IMP. gallons on the inner scale, and LITERS “▲” on the
outer scale corresponds to about “63.5” liters on the inner scale.
