English
TACHYMETER
(for models with tachymeter scale on the dial)
To measure the hourly average speed of a vehicle
1
2
Use the stopwatch to determine how many seconds it takes to go 1 km or 1 mile.
Tachymeter scale indicated by STOPWATCH second hand gives the average speed per hour.
Ex. 1 |
|
|
| 25 | 30 |
STOPWATCH | 5 | |
20 | 10 | |
second hand: |
| |
| MIN. |
40 seconds
Tachymeter scale: “90”
“90” (tachymeter scale figure) x 1 (km or mile) = 90 km/h or mph
14
*Tachymeter scale can be used only when the time required is less than 60 seconds.
Ex. 2: 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 tachymeter scale:
“90” (tachymeter scale figure) x 2 (km or mile) = 180 km/h or mph
“90” (tachymeter scale figure) x 0.5 (km or mile) = 45 km/h or mph
