takymetreillä

Takymetreillä is a Finnish term that translates to "with tachymeters" or "using a tachymeter" in English. A tachymeter is a scale found on the bezel of a wristwatch that allows the wearer to measure speed based on elapsed time. It is a type of chronograph function that utilizes the relationship between distance, speed, and time.

The tachymeter scale is typically marked with numbers that represent the time it takes to complete one unit of distance (e.g., one mile or one kilometer). To use it, one starts the chronograph when passing a known distance marker and stops it when reaching the end of that distance. The number on the tachymeter scale that aligns with the chronograph's second hand at the moment it stops indicates the average speed in units per hour. For example, if it takes 30 seconds to travel one mile, the tachymeter would read 120, meaning the speed is 120 miles per hour.

Watches equipped with tachymeter scales are often referred to as "tachy-watches" or "tachymeter watches." They are popular among enthusiasts of racing, aviation, and other activities where speed measurement is relevant. The functionality is a classic complication in watchmaking, often associated with robust and sporty timepiece designs. The precision of the tachymeter reading depends on the accuracy of the chronograph movement and the user's ability to start and stop the timer precisely.