Comparison Casio PRT-B50-1 vs Casio Pro-Trek PRG-240-1

A caliber can be described as the type of movement used in a watch. It is expensive and impractical to design a unique movement for each watch model, so most manufacturers often use the same movement in different watch models, sometimes with significantly different designs. The term "caliber" is due to the fact that initially the type of movement was designated by a number (in inch lines) corresponding to its largest size; however, today unique names or alphanumeric indices that are not directly related to sizes are widely used.

Knowing the name of the caliber on which the watch you are interested in is built, you can, if desired, find more detailed information about the mechanism and determine how its characteristics meet your requirements.

The watch has a separate second hand. Note that the location and features of the operation of such an arrow may be different. So, in some watches it is installed on the same axis with the rest of the hands, in others a separate small dial is provided for counting seconds. On some models, the second hand is part of the chronograph (see Features/Features) and only moves when the chronograph is on.

The accuracy of the rate is usually determined by the largest error — the deviation from the reference time, which can occur in a month when the watch is constantly running in normal mode. Accordingly, the smaller the number in this paragraph, the more accurate the clock. In addition, the accuracy of the movement is a kind of status indicator: if the error exceeds the values stated in the characteristics, this may indicate a malfunction in the mechanism.

If the accuracy indicators are the same both in advance and in lag, one number is indicated in the characteristics — for example, 30 sec / month (i.e. +/-30 sec / month); however, many mechanisms have unequal deviations, for example -15/+25 sec/month. Also note that this parameter is relevant only for quartz watches (see “Movement type”): in mechanical models, the accuracy of the rate is noticeably lower, it is measured in seconds not per month, but per day.

The power source of a quartz watch (see "Movement type") — in other words, the type of power source used in it.

— Battery. A miniature battery, usually in the form of a characteristic "pill"; used exclusively in quartz watches (see "Movement type"). The main disadvantage of this option can be called the need for replacement when the charge is exhausted; at the same time, almost all replaceable elements of miniature standard sizes used in wristwatches are produced only in the format of disposable batteries, without the possibility of recharging. On the other hand, they provide a long time of work, are inexpensive and are sold almost everywhere.

— Solar battery. Power supply system consisting of a photocell and a built-in battery. The photocell generates electricity when exposed to bright light, and the battery stores this energy and feeds the watch mechanism. The convenience of such models lies in the fact that with the regular presence of solar (or at least bright artificial) light, the owner does not have to worry about the energy reserve. On the other hand, the photocell significantly affects the price, and if you constantly stay indoors or wear clothes with sleeves that cover your watch, it becomes practically useless. Therefore, this option has not received wide popularity, and it is worth paying attention to such models primarily because they are regularly and a lot outdoors and/or in...bright daylight.

— Autoquartz movement (“kinetic”). A kind of automatic winding (see above), used in quartz watches. This technology was originally released by Seiko under the name "Kinetic", but nowadays it can be found in other manufacturers. Anyway, such systems work similarly to mechanical self-winding — transforming the energy from the movement of the user's hand into the energy necessary for the operation of the mechanism. However, in this case, such a mechanism does not start the spring, but rotates a miniature generator that generates electricity. The resulting charge is stored in a special capacitor and used to operate the quartz movement. Models with such mechanisms are positioned as "quartz watches in which you do not need to change the battery", and in general it is so. At the same time, they have the same limitations as conventional self-winding devices — in particular, with a sedentary lifestyle, this technology is practically useless. Yes, these watches are quite expensive.

— Arrow. A classic-looking dial with divisions to indicate the time and at least two hands — hour and minute — moving in a circle. This option limits the ability to display additional information and any additional function significantly complicates the design, but this classic allows you to make watches in any design, which is so appreciated.

— Digital. As the name implies, the time in such a watch is displayed by numbers, while the role of the dial itself is played by a liquid crystal screen. It is this type of watch that is commonly called "electronic". LCD screens are much more convenient for displaying additional information than arrow dials, they provide more options (for example, a stopwatch can easily count tenths and even hundredths of a second).

— Mixed. An option that combines both of the above types. Usually it is an arrow dial, supplemented by a small LCD screen. Thus, in one model, the advantages of both types of dials are combined — the visibility of the arrows and the versatility of the screen. Watches of this type can only be quartz.

— LED. In fact, it is a variation of the digital dials described above, in which LED screens are used instead of LCD matrices. The key feature of such watches is that they are, by definition, backlit — in the sense that the image itself glows. In addition, the colour of the image may vary, and many o...f these models have a bright and unusual appearance. On the other hand, such dials consume more energy than traditional liquid crystal ones, which consequently affects battery life. In some models, this moment is partly offset by the fact that the screen does not work all the time, but turns on for a few seconds at the touch of a button; however, this also creates certain inconveniences — in order to find out the time, you have to make extra movements.

— Disk. A rather unusual type of dials based on the use of rotating disks with numbers printed on them. There are virtually no arrows in the disk dials, their role is played by special windows in which the readings of a particular disk are displayed. Such watches differ in their original appearance, but in terms of convenience they are still somewhat inferior to traditional watch models (especially since the second hand — or rather, the disk — is usually not provided for in their design). Thus, this option has not received much distribution.

The type of markup used on the main watch face. This parameter is relevant for models with hands (see "Dial Type"), while the type of marking is indicated only on the main scale — additional marks on the bezel are not taken into account (although markings on the additional world time dial may be taken into account).

This parameter does not affect the functionality of the watch, and the choice depends solely on the tastes of the owner. The main types of markings found in modern watches include Arabic and Roman numerals (which can be supplemented with marks), a combination of these numbers, as well as the simplest marks themselves. Here are the main features of these options and their combinations:

— Arabic. Dials that have marks only in the form of Arabic numerals — that is, standard modern numbers "1", "2", etc. In this way, both all divisions of the dial, and only some of them (for example, 3, 6, 9 and 12 o'clock). However, anyway, there are no other types of marks in such watches.

— Roman. Dials that are marked only in the form of Roman numerals — combinations of the symbols I, V, X. This marking gives the watch a peculiar style, but it can take some getting used to — and therefore is less common than Arabic numerals. Again, in this case we are talking about dials that do not carry any other designations, excep...t for numbers of this type.

— Tags. Minimalistic design, in which the divisions on the dial are indicated only by a label, without a signature. Most often, marks are applied to all twelve hours; exceptions to this rule are possible, but they are rare nowadays. It should be noted that such a design can be found both in classic watches with minimal functionality and in advanced models with extensive features: in the first case, the marks give the product a neat appearance, in the second, they save space on the dial for additional scales and markings. Theoretically, such markup is not as convenient as notation with numbers; however, almost all dials in modern wristwatches use a 12-hour scale with a standard location of marks, so with a little habit you can completely do without numbers — the position of the mark on the scale already carries enough information.

— Arabic + Roman. Dials that combine both types of numbers described above at once (sometimes also with marks; in this case, the presence of marks is not specified). The most popular type of watch with this feature is the world clock (see "Features and Features"), where one dial is marked with Arabic numerals and the other with Roman numerals. There is also a combination of these symbols on the same scale — for example, when 3 and 9 hours are indicated by ordinary numerals, and 6 and 12 by Roman numerals. However, neither one nor the other variant received special distribution.

— Labels + Arabic. Dials, in which part of the markings are applied with Arabic numerals, part with marks (for both, see above). Moreover, the ratio of both can be different: for example, in some models there is only one digit (usually "12"); in others, key positions "3", "6", "9" and "12" are designated by numbers; thirdly, part of the dial is occupied by a display, near which the numbers simply do not fit and you have to manage with marks, etc.

— Marks + Roman. The dials, in which part of the markings are applied with marks, part with Roman numerals. This markup method is generally similar to the “labels + Arabic” option described above (and can also provide different design options).

Clock face background colour. Indicated for models with pointer or combination dials (see "Dial type"); in purely electronic models, usually, either a grey substrate (for conventional LCDs) or a dark base (for LEDs) is used.

The most popular in modern watches are black, white, silver and blue dials. However, in addition to this, other shades can be found on the market — in particular, beige, yellow, green, golden, brown, red, orange, pink, grey and purple. A special case are watches with chameleon glasses (see below).

Some models are available in several colour options, in such cases these options are listed separated by commas — for example, "white, red, silver." If the dial is painted simultaneously in 2 or 3 colours, they are indicated as a combination — for example, "white with red" or "white with yellow and red". And multi-coloured models include models in which more than 3 colours are used for the dial.

A function found in models with mixed dials (see the relevant paragraph) or additional scales. One of the disadvantages of such models is that in a certain position, the hands can cover the screens or scales, making it difficult to read the information on them. For such cases, the function of moving the hands is provided: at the user's command, the hands move to a position in which they do not cover additional elements of the dial. Also, on command, the arrows can be returned “to their place”; in addition, in some models, the return occurs automatically after a certain time.

How to illuminate the clock face.

— Luminescent coating. A variant used in pointer dials: the hands, and sometimes the scale, are coated with a “phosphorus” coating that glows in the dark. This method of backlighting is inexpensive and can be used even in low-cost models; in addition, it does not require batteries and is suitable even for mechanical watches. On the other hand, coverage is often not as effective as it should be. The fact is that for work it must be “charged” from the sun or another bright light source, and this “charge” is enough for an average of 5-6 hours, and already in the first couple of hours the brightness of the glow drops noticeably.

— Electronic. Illumination based on LEDs or other miniature light sources. Usually, it does not work constantly, but turns on and off by pressing a special button; the exception is LED dials (see "Dial Type"). The main advantage of electronic backlighting is efficiency: it is guaranteed to be enough to view the image on the dial. In addition, such systems do not depend on external illumination, in contrast to the luminescent coatings described above. On the other hand, the lighting requires a battery to operate; therefore, this type of illumination is found exclusively in quartz watches (see “Mechanism type”).

— Luminescent coating / electronic. Systems that combine both types of illumination described above. This option is f...ound mainly among models with combined dials: the hands are coated with a luminous coating, and the electronic backlight is intended mainly for displays and additional scales (and also as a backup option for the hands). The combined backlight is very convenient, however, such watches are somewhat more expensive.

— Tritium illumination. Illumination option found on premium pointer dials. Miniature flasks filled with tritium, a radioactive form of hydrogen, are responsible for the illumination in such models; from the inside, the surface of such flasks is covered with a phosphor, which glows under the influence of tritium radiation. Separately, we note that this radiation does not pose a danger to humans: it does not go beyond the bulb, and even inside its intensity is extremely low. Tritium illumination is expensive, but it is extremely convenient from a practical point of view: "flashlights" work constantly, without batteries and regardless of external lighting, and shine significantly brighter than a conventional luminescent coating. However due to the decay of tritium, they gradually lose their brightness, but this happens very slowly: it takes 12 years to reduce by half, and at least 20 years for the backlight to become useless.