Measurement range
The range at which the device remains fully operational without the use of additional receivers (see below); in other words, the radius of its action without auxiliary devices.
In some models, a range may be specified that shows the minimum (
3 cm,
5 cm) and maximum measurement ranges. But in most cases, only the maximum value is indicated.
The specific meaning of this parameter is determined by the type of instrument (see above). So, for optical levels, the measurement range is the greatest distance at which the operator can normally see the divisions of a standard leveling staff. For laser levels, this parameter determines the distance from the device to the surface on which the mark is projected, at which this projection will be easily visible to the naked eye; and in rangefinders we are talking about the greatest distance that can be measured. Typically, the measurement range is indicated for ideal conditions - in particular, in the absence of impurities in the air; in practice, it may be less due to dust, fog, or vice versa, bright sunlight "overlapping" the mark. At the same time, tools of the same type can be compared according to this characteristic.
Note that it is worth choosing a device according to the range of action, taking into account the features of the tasks that are planned to be solved with its help: after all, a large measurement range usually significa
...ntly affects the dimensions, weight, power consumption and price, but it is far from always required. For example, it hardly makes sense to look for a powerful laser level at 30-40 m if you need a device for finishing work in standard apartments.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”.
Accuracy
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.
Leveling time
Approximate time it takes for the self-levelling mechanism to bring the level to a perfectly level position.
For more information on such a mechanism, see Self-Level Limits. And the actual time of its alignment directly depends on the actual deviation of the device from the horizontal. Therefore, in the characteristics, usually, the maximum alignment time is given — that is, for the situation when in the initial position the device is tilted to the maximum angle along both axes, longitudinal and transverse. Since the levels are far from being installed in this position, in fact the speed of bringing to the horizontal is often higher than the claimed one. Nevertheless, it makes sense to evaluate different models precisely according to the figures stated in the characteristics — they allow you to estimate the maximum amount of time that will have to be spent on alignment after the next movement of the device. As for specific indicators, they can vary from 1.5 – 2 s to 30 s.
Theoretically, the shorter the alignment time, the better, especially if there are large volumes of work ahead with frequent movements from place to place. However, in fact, when comparing different models, it is worth considering other points. First, we reiterate that the rate of leveling is highly dependent on the leveling limits; after all, the greater the deviation angles, the more time it usually takes for the mechanism to return the level to the horizontal. So, to directly compare w...ith each other in terms of the speed of self-leveling, it is mainly those devices in which the permissible deviation angles are the same or differ slightly. Secondly, when choosing, it is worth considering the specifics of the proposed work. So, if the device is to be used frequently on very uneven surfaces, then, for example, a model with a leveling time of 20 s and self-levelling limits of 6 ° will be a more reasonable choice than a device with a time of 5 s and limits of 2 °, since in In the second case, a lot of time will be spent on the initial (manual) installation of the device. And for more or less even horizontal planes, on the contrary, a faster device may be the best option.
Operating temperature
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.
Tripod thread
The standard size of the thread used to mount the level/rangefinder on a tripod (if available). This option can be useful if you already have a surveying tripod that you want to use with the tool.
The most popular options in modern devices are 1/4" and 5/8". It is worth noting that 1/4" is a standard size for
photographic equipment - accordingly, levels with such a thread can be installed even on ordinary
photographic tripods.
Diode emission
The wavelength of the radiation emitted by the LED of the level or rangefinder; this parameter determines primarily the colour of the laser beam. The most widespread in modern models are LEDs with a wavelength of about 635 nm — at a relatively low cost, they provide bright red radiation, giving a well-visible projection. There are also green lasers, usually at 532 nm — the marks from them are even better visible, but such LEDs are quite expensive and rarely used. And radiation with a wave longer than 780 nm belongs to the infrared spectrum. Such a laser is invisible to the naked eye and is poorly suited for leveling, but it can be used in rangefinders — of course, with a viewfinder (see "Type" for more details).
Mains powered
The ability to power the device
from a household electrical outlet, in other words, a regular outlet.
Modern levels and rangefinders are powered by batteries or accumulators by default. With all its advantages (first of all, freedom of movement and independence from sockets), this power supply method also has serious disadvantages: limited operating time, as well as the need to buy additional batteries or look for a power source to charge the battery (and the charging procedure also takes quite a long time). ). Thus, some modern appliances additionally provide the possibility of connecting to a power outlet and operating from the mains. This primarily allows you to save battery power; and many models are also capable of recharging batteries (built-in or even removable) in the process.
Note that the ability to work from the network is found mainly among traditional laser levels, and at different levels — from compact household models to fairly powerful professional equipment.
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).