Seiko 6M25 Manual - Page 18

English TACHYMETER (for models with tachymeter scale on the dial) To measure the hourly average speed of a vehicle 1 Use the stopwatch to determine how many seconds it takes to go 1 km or 1 mile. 2 Tachymeter scale indicated by Second hand gives the average speed per hour. Ex. 1 Second hand: 40 seconds Tachymeter scale: "90" "90" (tachymeter scale figure) x 1 (km or mile) = 90 km/h or mph * 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 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 18