Type
General type of device.
Modern levels differ primarily in their operating principle: they are
optical(traditional or
digital) and
laser(conventional and
rotary). At the same time, the specific specialization depends on the principle of operation - laser and optical devices differ in purpose and application. In turn, the main function of rangefinders is clear from the name - determining distances. The difference here also lies in the principle of operation: most modern rangefinders are
laser, but there are also more specific
ultrasonic devices.
Here is a more detailed description of each of these varieties:
— Optical level. Levels have a traditional design - in the form of a kind of specialized telescope mounted on a tripod and supplemented with measuring scales (including in optics, in the operator’s field of view), as well as devices for horizontal alignment (compensators, levels). Such devices are used to determine height differences using the so-called geometric leveling method, for which leveling rods are also used - special strips with measuring scales installed vertically. And the general principle of this method is as follows: the operator points the level’s telescope, set horizontally, at the vertical leveling staff, and determines
...which mark on the staff is opposite the main “sighting mark” of the level - this mark will correspond to the actual height of the device. More information about this method, including specific measurement techniques, can be found in special sources. Here we note that optical levels are excellent primarily for working in large areas of open areas; they are used mainly in such fields as geodesy and cartography. But for work where you have to deal with relatively short distances (primarily construction in small areas), such devices are not suitable; However, they are quite complex and expensive, especially compared to laser devices. So, relatively few optical levels are produced nowadays.
— Digital level. In fact, it is an advanced version of the optical levels described above. Externally, they differ primarily in that instead of a regular telescope, such devices are equipped with a digital camera that displays the image on the screen on the control panel. Such levels are used in the same way as “regular” optical ones, but the operating procedure itself is automated and supplemented with a number of advanced functions. Thus, in most models, the operator does not need to manually count the slats, record the results and carry out calculations - the device itself recognizes the recorded marks, stores them in memory and processes the received data, displaying the final result. It is often possible to save information to a memory card or other media, copy it to a PC, or even connect the level to a laptop and use special software (for example, mapping) directly during measurements. On the other hand, such opportunities are not cheap: digital levels are several times, or even orders of magnitude, more expensive than traditional optical ones. So, in general, devices from this category are high-quality devices, designed primarily for professional use - when you often have to deal with large volumes of work, in light of which speed and ease of data processing are of key importance.
— Laser level. A kind of laser projectors that display marks on walls and other surfaces - usually in the form of lines, but there are also models with a dot function (for more details, see “Point projections”) or even only dot ones (see “Purpose”). A classic laser device actually combines the functions of a level and a building level: it can be used both for the above-described geometric leveling using slats, and for constructing planes and marking lines (some models are equipped with mechanisms that allow you to arbitrarily select the angle of inclination). Such devices are well suited for working at short distances, including indoors; and thanks to their relatively simple and inexpensive design, they are very popular, especially in construction. At the same time, we note that some models can have a fairly significant measurement range - up to 50 m on their own and up to 150 m or more using special receivers.
We emphasize that this paragraph includes traditional laser levels, in which the mark line is formed by scattering the beam with a special prism. Rotary models that operate by rotating the emitter are included in a separate section and are described below.
— Rotary level. A variation of the laser levels described above, in which the plane is “drawn” not due to the scattering of the laser beam in the prism, but due to the rapid rotation of the emitter. As a result, the trace from the beam merges into one continuous line for the eye. Rotary levels are usually not cheap and most of them are professional devices designed to work on large areas. The measurement range without a receiver is usually several tens of meters, and with a receiver - up to several hundred. In light of this, when using such devices, you need to be especially careful about observing safety rules - getting a powerful laser beam into your eyes can cause harm to your health, and even the reflection of a laser “bunny” from some surfaces often causes discomfort. So, it is highly advisable to use safety glasses or masks in the operating area of the rotary device.
- Laser rangefinder. Devices for measuring distances using a laser beam. The key advantage of such devices over rulers, tape measures, etc. is that you do not need to move during the measurement process - just place the device at the starting point and point the beam at the object, the distance to which you want to determine. At the same time, the range of action in many models reaches 100 m or more, and the error does not exceed a few millimeters, or even fractions of a millimeter. In addition, modern laser rangefinders can be equipped with various additional functions such as automatic calculation of area and volume, summation of distances, fixation of minimum and maximum, etc. The disadvantages of such devices include reduced efficiency in the presence of fog, heavy dust or other similar contaminants air, as well as difficulties in measuring distances to glass and other transparent objects that transmit the laser beam rather than reflect it. However, these moments are not so often critical, and in terms of performance characteristics, laser devices are noticeably superior to ultrasonic ones. Therefore, this type of rangefinder is the most popular in our time.
— Ultrasonic rangefinder. Range finders using ultrasound; In such devices, a laser is also often installed, but it is intended solely for precise pointing at the desired object and is not used for measurements. In any case, rangefinders of this type are good because their effectiveness practically does not depend on the purity of the air and the type of surface on the object being measured: ultrasound works perfectly through dust, smoke, fog, etc., and is also reflected perfectly from glass and other transparent materials. laser materials. On the other hand, in terms of “range” and accuracy, such devices are noticeably inferior to laser ones: the measurement range in them does not exceed 15 - 20 m, and the error is calculated not in millimeters, but in percentages - usually about 0.5 - 1% (which, for example, at a distance of 10 m corresponds to an actual error of 5 - 10 cm). As a result, rangefinders of this type are much less common than laser ones these days.Measurement range (with receiver)
The longest measurement range provided by a laser level (see “Type”) when using a special receiver with a photocell.
Thanks to its sensitivity, such a receiver is able to respond even to a weak laser beam, the mark from which is no longer visible to the naked eye; At the same time, the area of the photocell is quite large, and special indicators make it possible to determine the exact position of the mark. Among other things, this significantly expands the range of action of the level - the measurement range with a receiver is usually several times greater than without it. On the other hand, such equipment inevitably affects the overall cost of the device; and in some models the receiver
is not included in the package at all; it must be purchased separately. However, the second option also has its advantages: you do not need to immediately pay for an additional accessory, it can be purchased later, when a real need arises, while some models allow you to choose the optimal receiver model from several options at your discretion.
Note that the receiver can be useful not only for increasing range; These points are described in detail in paragraph “Included parts”.
Beam angle (horizontal)
The sweep angle in the horizontal plane provided by the level emitter. If there are several emitters, their total coverage angle is indicated here; a typical example of such devices are models for full 360 °, not related to rotation.
Actually, all rotary devices, by definition, provide a coverage of 360 °. Therefore, it is worth paying attention to this parameter in cases where we are talking about more traditional laser levels. And here it is worth considering that a larger coverage angle, on the one hand, can provide additional convenience, on the other hand, it increases the price and power consumption of the device. So when choosing, you should proceed from real needs; detailed recommendations on this subject can be found in special sources.
Operating time
Operating time of the device on one battery charge.
It is worth considering that these figures are quite approximate, since the operating time is measured under certain standard conditions (usually continuous operation at nominal power). And since in practice conditions may differ markedly, the operating time may turn out to be noticeably shorter or longer than stated. In addition, if the device uses replaceable batteries (AAA, AA and the like), then autonomy will also depend on the quality of the specific batteries/accumulators. Nevertheless, based on the data specified in the characteristics, it is quite possible to evaluate the capabilities of specific models and compare them with each other: the difference in the declared operating time, as a rule, proportionally corresponds to the difference in practical autonomy under the same conditions.
We also note that the operating time is specified mainly for levels; in rangefinders another parameter is more often used - the number of measurements (see below).