Comparison Bosch GOL 26 D Professional 0601068002 vs DeWALT DW096PK

Accuracy is described as the maximum deviation from the true value of the measured parameter, which the device can give if all the rules for its operation and the corresponding measurements are observed. In both rangefinders and levels, this parameter is usually designated for a certain distance — for example, 3 mm at 30 m; but even for one manufacturer, these "control" distances may be different. Therefore, in our catalog, the accuracy of all devices is recalculated for 1 m distance; with such a record, for the example above, it will be 3/30 \u003d 0.1 mm / m. This makes it easier to compare different models with each other.

It is also worth mentioning that the meaning of the "accuracy" parameter for different types of measuring instruments (see "Type") will be different. For optical levels, it is described in the "SKP" paragraph above. For laser levels of all types, accuracy is the maximum deviation of the mark from the true horizontal (or vertical, if such a function is provided), and for the horizontal, we can talk about both moving the mark up / down and turning it. In rangefinders, this characteristic describes the maximum difference (both in "plus" and "minus") between the readings of the device and the actual distance to the object.

Anyway, the smaller the error, the better; on the other hand, accuracy significantly affects the price of the device. Therefore, it is necessary to choose a specific model for this parameter, taking into account the...specifics of the planned work. For example, for a relatively simple repair in a residential apartment, a high-precision tool is unlikely to be required; and recommendations for more complex tasks can be found in specialized sources, ranging from expert advice to official instructions.

The diameter of the lens of the optical level (see "Type"). First of all, the aperture ratio, the amount of light transmitted by the optical system, depends on this parameter. The larger the lens diameter, the higher this number and the brighter and clearer the image visible to the operator is, which is especially important in low light conditions (in cloudy weather, at dusk, etc.). In addition, a large lens allows you to increase the angle of the field of view; for more on this, see p. "Magnification".

The root mean square measurement error that occurs during the operation of an optical or digital level.

This indicator is noticeably lower than the deviation indicated in the “Accuracy” paragraph: if the accuracy is indicated in millimeters per meter, then the SKP is in millimeters per kilometer (more precisely, the so-called “double-track kilometer” - a route 500 m long, traveled there and back). There are no contradictions here: the SKP describes exclusively the error caused by the imperfect design of the device itself and arises under absolutely ideal measurement conditions, while the accuracy characterizes the “level-staff” system and describes deviations that are relevant for real conditions. Therefore, SKP as a whole is a formal parameter used to divide levels into accuracy groups - high-precision, precision and technical. The first category includes devices with SCP up to 1 mm/km, the second - up to 3 mm/km, and the third - all less accurate. The minimum accuracy groups required for certain types of work are described in special sources - in particular, regulatory documents and instructions.

The smallest focal length of an optical or digital level (see "Type").

The focal length in this case means the smallest distance to a leveling staff or other object at which the device can clearly focus on it. In most modern levels, this distance does not exceed 1.5 m, and in some models it is about 20 cm at all. So, from a practical point of view, this is more of a reference than a really significant parameter — after all, such devices are used at much greater distances. At the same time, with similar basic characteristics, a shorter focal length, usually, means more advanced and high-quality optics.

The width of the field of view provided by the lens of an optical or digital level (see "Type").

According to the general laws of optics, an increase in the magnification factor leads to a decrease in the angle of view; however, models with the same multiplicity may differ in this indicator. At the same time, on the one hand, the more extensive space the operator sees, the more convenient it is to work with the device, especially in the process of aiming at a leveling staff or other specific target. On the other hand, the difference between specific options is small and in fact it rarely turns out to be fundamental. A typical example: most 24x levels have an angle of view from 1° 20' to 1° 30', which at a distance of 100 m corresponds to a visible space diameter of approximately 2.32 m to 2.61 m. As you can see, the difference in diameters is only about 29 cm, and at shorter working distances it decreases proportionally.

Thus, from this point of view, the viewing angle is more of a reference than a really significant parameter during operation. At the same time, it is worth noting that a wider field of view is often a sign of a more advanced instrument, which, in particular, has a larger lens — and this feature has quite practical advantages (for more details, see "Lens Diameter").

The working range of the compensator installed in the level.

A compensator is a device for smoothing out small deviations of the device installed in the working position. This function is especially important for optical and digital models, in which it is mainly used. Do not confuse it with auto-leveling: the latter is used during the initial installation of the level, and the compensator absorbs small shocks that occur already in the process of work (a typical example is ground vibration from heavy construction equipment nearby). And the range is indicated by the maximum deviation from the horizontal, which such a mechanism can eliminate.

These values in modern levels are small, they are calculated in arc minutes and usually range from 12 – 15' to 30'. At the same time, the wider the range of the compensator, the more efficient it is, the stronger shocks and vibrations it can smooth out; on the other hand, increased efficiency inevitably comes at a price. Also note that compensators can differ in the type of damper (see below).

The temperature range at which the device is guaranteed to work for a sufficiently long time without failures, breakdowns and exceeding the measurement error specified in the characteristics. Note that we are talking primarily about the temperature of the device case, and it depends not only on the ambient temperature — for example, a tool left in the sun can overheat even in fairly cool weather.

In general, you should pay attention to this parameter when you are looking for a model for working outdoors, in unheated rooms and other places with conditions that are significantly different from indoor ones; in the first case, it makes sense to also make sure that there is dust and water protection (see "Protection class"). On the other hand, even relatively simple and "myopic" levels / rangefinders usually tolerate both heat and cold quite well.

The level of protection against harmful influences (in the first place — the penetration of foreign objects) that the body of the level / rangefinder provides in accordance with the IP standard. This standard describes two separate characteristics — protection against solid objects and against water. They are designated respectively by the first and second digit after the IP index; the higher the number, the higher the degree of protection.

Considering that levels and rangefinders usually have to work on construction sites where there is a lot of dust, the minimum level of protection against solid objects for such tools is the fifth. It allows some dust to get inside, but in such a way that it does not affect the performance of the device. The maximum level of dust resistance is 6, which implies complete protection from solid particles.

The second characteristic, protection against moisture, in levels and rangefinders is usually indicated starting from level 4. Officially, it provides protection "against spray from any direction", in fact this means that it can be used in moderate rain with strong winds — a useful point in that if the tool is to be used outdoors. Level 5 allows operation during storms and downpours, a device of the sixth class can withstand being hit by a wave, the seventh — a short-term immersion under water up to 1 m, and the eighth — even a long stay under water. However, for a conventional construction tool, too high water resistance i...s usually not required.

Actually, the most popular option in modern construction tools is the IP54 class: it is quite enough even for work in bad weather, while such cases are relatively inexpensive. There are also more protected models, but less often.

It is also worth noting that a certain level of dust and water protection in itself is usually provided even in devices that do not have an IP marking. The absence of this index does not necessarily mean the absence of protection — it only says that the case has not been officially certified according to the IP standard. But if you need an additional guarantee of reliability, you should still pay attention to certified options.

— holder. Devices for fixing the level / range finder on various surfaces. Such a device differs from a tripod primarily in its small size — within a couple of tens of centimeters. On the other hand, most holders allow you to install the device not only on horizontal, but also on vertical surfaces — for example, walls (and some are exclusively wall-mounted). Anyway, this function greatly expands the installation possibilities.

— Receiver. laser radiation supplied with the device. This device is usually equipped with laser levels, less often with rangefinders, and it is not required at all for optical instruments. The main purpose of the receiver is situations where the laser mark is not visible to the naked eye — for example, at a long distance or in bright light. More details on the features of its application are described above in the paragraph “Measurement range (with receiver)”.

— Tripod. Most modern instruments have a standard size thread and can be used with any suitable tripod. On the other hand, a complete tripod is most often specially designed for a certain model and optimally matches it in terms of general characteristics. In addition, this configuration option relieves you of the need to look for and purchase a suitable tripod yourself.

— Case / case. The main function of these devices is...to protect the device from bumps, scratches, dirt, temperature changes and other adverse effects; for this, of course, improvised means can also be used, but specialized protection is usually both more convenient and more reliable. In addition, almost all cases and most covers greatly simplify the transportation of the tool — in particular, due to the fact that they can also be used for complete accessories.

— Remote control. Among rangefinders and optical levels, this function is practically not found, because. working with them involves the constant stay of the device in the hands of the operator. But for laser levels that require you to regularly move from the device to the surface to be marked and back, the remote control can be a very useful addition — due to the fact that it minimizes such movements. For example, after marking the "front of work" on the wall according to the projection from the level, you do not have to approach the device to turn it off — just give a command from the remote control. At short distances, the savings in time and effort may not be so obvious, but over large areas, they can become quite noticeable.