TACHOMETriC SCALE
A .tachometer .(or .tachymeter) .is .a .device .that .measures .
average .speed .over .a .set .distance . .It .can .be .used .to .check .
accuracy .of .a .car's .speedometer, .for .example .
A .road .distance .of .1 .Kilometer .or .1 .mile .is .generally .taken .
as .a .basis .
A
uSiNg A TACHOMETEr
1 . . . As .the .car .passes .point .
pressing .button ."A" . .
2 . . . The .moment .the .car .passes .point .
Kilometer, .press .button ."A" .again . .The .chronograph .will .stop .
3 . . . On .the .outer .tachometric .scale, .the .chronograph .second .
hand .indicates .a .figure .that .represents .the .average .speed .
in .miles .or .Kilometer .per .hour, .according .to .the .distance .
basis .selected .
1 Mile/km
A
, .start .the .chronograph .by .
B
, .i .e . .after .1 .mile .or .1 .
B
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