Tachymeter - Seiko V657 Instructions Manual

TACHYMETER

[for models with tachymeter scale on the dial]
To measure the hourly average speed of a vehicle:
Tachymeter scale: 90
STOPWATCH second hand:
40 seconds
Ex. : "90" (tachymeter scale figure)
x 1 (km or mile) = 90 km/h or
mile/h
1
Use the stopwatch to determine how many
seconds it takes to go 1 km or 1 mile.
2
Locate the second marker on the main dial
which corresponds to the number of seconds
measured. The number on the tachymeter
scale indicates the average speed per hour.
* For the models with the tachymeter scale around the
small dial at the 6 o'clock position, read the tachymeter
scale which the STOPWATCH second hand points to.
Tachymeter scale can only be used to measure average
speed when time required is up to 60 seconds.
If the measuring distance is extended to 2 km or miles or
shortened to 0.5 km or miles and STOPWATCH second
hand indicates "90" on the tachymeter scale:
"90" (tachymeter scale figure) x 2 (km or miles)
= 180 km/h or mph
"90" (tachymeter scale figure) x 0.5 (km or miles)
= 45 km/h or mph
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