How to use a Tachymeter in watches
A tachymeter scale is a function which is usually inscribed around the rim of a dial or the bezel. It is
used to compute speed on the basis of time travelled or can measure distance based on speed. A
tachymeter is also used to calculate the number of tasks you can complete in a given time. The
tachymeter scale on a watch generally starts at 500-700 and decreases as time elapses. The spacing
between the marks on the tachymeter dial are therefore proportional to 1/t where t is the elapsed
time, and hence the tachymeter scale is logarithmic and noticeably non linear. The simple equation
to time versus speed and distance is used in calculation with a tachymeter.
When you are using a tachymeter to calculate speed
you can use the equation T=3600/t, where T stands
for the tachymeter scale value,
(t) is the elapsed time and 3600 is the number of
seconds in an hour.
When using a tachymeter to calculate distance, you
first need to know the travelling speed (d).
Start at the zero-seconds reading, and end once your
tachymeter reading is your travelling speed. For
example, say your speed is 75 mph. Once the
tachymeter reading reaches 75, then you have
travelled 1 mile. For this measurement to work,
speeds must always remain at a constant 60 mph (or
60 of another unit of measurement) or faster.
Some tachymeter scales are on a rotating, indexed bezel. This allows two additional modes of use:
The tachymeter bezel can be aligned with a free running second hand, and, more subtly, can be used
to find the average speed over longer times/distances.
TO Read more about Luxury Swiss Watches with tachymeter, please visit the website
http://www.ethoswatches.com/ .