The knowledge of watch bezels

In addition to being used to identify the current time, watches can also be equipped with many complications. Many of these complex functions are achieved through the bezel: from calculating the diving time to measuring the speed of the car; from measuring the fuel supply to estimating the distance to the fire; from determining the latitude and longitude to knowing the time anywhere in the world… The amount of work that can be done with a border is beyond imagination. Today, let's briefly talk about the bezels and see how the various bezels are used.

Everyone should be familiar with the diving bezel. It is a sharp tool used by divers to calculate diving time. According to the ISO 6425 standard, the diving bezel must be unidirectional, equipped with a 60-minute scale, and the scale interval must be subdivided into 5 minutes, and there must be a luminous marker (usually a triangle or diamond) at the 60-minute position to determine Minute reading.

In fact, many diving bezels have surpassed this standard now. Their scale intervals between 0 and 15 minutes (sometimes extended to 20 minutes) are refined to 1 minute, and they are made of luminous materials or different colors. This is highlighted because the last 15 minutes are especially important for a diver's decompression. The Fifty Fathoms and the Water Ghost were the first to do this, and now, this bezel has become one of the standard designs of diving watches.

The diving bezel is also very simple to use, just twist the bezel until its triangular (or diamond) mark is aligned with the current minute hand position, and as the minute hand moves forward, you can visually observe the elapsed time. Another method is to rotate the triangle (or diamond) mark to the time of leaving the water after deciding the diving time, and you can intuitively see how long you can stay underwater through the advance of the minute hand. This can also explain why the diving bezel must be unidirectional, because if you accidentally turn it a little more underwater, it will only "shorten" your underwater time instead of the other way around, which greatly increases safety.

Many times, the diving bezel is placed on the outside of the dial, but there are also inner diving bezels. To adjust this kind of bezel, of course, it cannot be screwed directly, it can only be adjusted by adding an additional crown.

The countdown bezel is a variant of the diving bezel. Unlike the diving bezel, its scale is set counterclockwise. This kind of bezel is mostly used in military watches to meet the needs of combat, such as counting down after launching bombs, etc. The method of use is also similar to that of a diving bezel - by rotating the bezel to make the hands point to a specific position, when the hands move to the "0" scale, the expected event will occur.

The tachymeter bezel is also a very common existence. Its main purpose is to measure the speed of an object traveling within a fixed distance, but it can also be used to achieve functions such as ranging. 

A tachymeter bezel is a little more complicated to use than a diving bezel, essentially converting elapsed time (seconds) into speed (km/h). The specific usage method is as follows: you are driving, assuming your starting point is point A, there is a 1KM sign on the road ahead, we will mark it as point B, so that we can know the distance between two points AB is 1 km. When you start from point A, press the chronograph, and the hands start to run. When you drive for a while and see the 1KM sign, it means that you have reached point B, which means that you have just traveled 1 km. Press the chronograph again at this time, the pointer stops, and the reading it points is your average speed during the 1 km driving.

First of all, we must make it clear that at the beginning of production, the speed measurement function is used at a length of 1 km by default. Then I will give an example to illustrate the production process of the speedometer bezel: if it takes you 30 seconds to walk 1 kilometer, then the distance you can walk in 1 hour is 3600/30=120 kilometers, in other words, at this time you The speed is 120 km/h.