Number of measuring vials
The number of bubble capsules for measurement provided in the design of the instrument.
For more information about such capsules, see “Type - Bubble”, however, they can also be equipped with other types of tools (except for hydraulic levels, which use a fundamentally different operating principle). Each capsule is responsible for its own parameter; accordingly, the more there are, the more extensive the capabilities of the tool, the more parameters can be controlled with its help. Specific options may be as follows.
— 1.
A single capsule, designed, as a rule, to control horizontality. This option is extremely rare, mainly in two categories of instruments - ultra-compact bubble-type pocket levels, up to 20 cm long, as well as protractors in which “bubble” measurement is not the main function.
— 2. A very common option in modern measuring instruments. Most often it provides
two capsules responsible for controlling the horizontal and vertical. However, one of the capsules can also be made rotary (for more details, see “Functions”).
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3. Perhaps the most popular option today. Typically, two capsules are responsible for the vertical and horizontal, and the third is installed at an angle of 45° and allows you to control the slope at this angle; Occasionally there are models where the third capsule is made rotating.
- 4. Th
...is option is typical mainly for long levels - from 150 cm or more. In such devices, the classic pair of capsules (“horizontal” and “vertical”) are duplicated on both sides of the bar. Thus, no matter which side the customer applies the level, a couple of capsules will appear in front of his eyes in any case, and he will not have to reach for the other end of the long tool.
— 5. The five-capsule design is typical for advanced bubble levels with specific capabilities. In such models, one “vertical” and “oblique” (45°) capsule is usually installed, but there are three “horizontal” capsules - one is installed level, and the other two have a slight slope (usually 1.5% and 3.5% ). Such equipment is required infrequently - only for some special tasks - therefore this type of level is not particularly widespread.Vials
The presence of capsules located at a certain angle makes it clear what can be expected from the use of the level. In addition to the classic
horizontal,
vertical and
at an angle of 45 °, there are others. For example
, a capsule for plumbing work or a swivel capsule. Such a capsule, usually, is supplemented with a goniometric scale, which allows it to be rotated to a clearly defined angle and to control whether the measured surface corresponds to this angle (relative to the horizontal or vertical). At the same time, we note that this function does not turn the level into an inclinometer. It is technically possible to measure the angles of inclination using a rotary capsule, but the accuracy of such measurements is not high, and the procedure itself turns out to be quite troublesome — it is easier to use the tool originally intended for this.
Accuracy
The measurement accuracy provided by the level, or rather, the maximum error that can occur during measurements.
In this case, linear accuracy is meant, measured in millimetres per metre. The meaning of this parameter can be described using an example as follows: if the tool has a length of 1 m, an accuracy of 1 mm / m and shows a flat horizontal line, the difference in height between its edges will be less than 1 mm. In the case of levels, such an indicator is clearer than the error in degrees. And for goniometers and inclinometers, the accuracy in mm / m is indicated mainly for horizontal and vertical measurements; for angular measurements, the accuracy in degrees is relevant (see below).
The
higher the accuracy, the better the tool, the less measurement errors it gives, however, this parameter also affects the price accordingly. Therefore, it rarely makes sense to specifically look for a high-precision level — for most work, an error of 1 – 2 mm per metre, provided by modern models, is considered quite acceptable.
Note that in the characteristics it is customary to indicate the minimum value of the error. This must be remembered in light of the fact that the measurement accuracy may vary in different modes — for example, for a folding tool (see "Functions") it is higher in the folded position.
Functions
—
Scale for measuring length. Own scale for measuring length, printed on a level or other tool; Essentially a built-in line. Constantly using a level instead of a ruler does not make sense because of the bulkiness, but this function can still be useful — for example, in situations where you suddenly need to measure something, but there is no ruler at hand.
—
Mirror capsule. The presence of a mirror capsule in the design of the tool. Such a capsule is, in fact, a regular vertical control capsule, supplemented with a special mirror. The usual "vertical" capsule is possible only from the front (wide) side of the instrument; thus, a tool without a mirror is useless for vertical control in cramped places, the width of which is less than the width of the rib (see above). But in the presence of a mirror capsule, the level can be inserted into the slot with a narrow side, and the position of the bubble will still be visible thanks to a special slot with a mirror installed in it.
— Hole for gripping. The presence of a special slot in the design of the level, which allows you to comfortably hold it in your hands. In devices with a large length of such slots, two can be provided, for both hands. Anyway, holding by the slot is often not only more comfortable, but also more reliable than the usual outside grip.
— Magnetic base. The presence of a magnetic base in the design of the tool. Such a
...base allows you to tightly “stick” to metal surfaces, which not only reduces the risk of dropping the tool, but also has a positive effect on measurement accuracy. Usually, powerful neodymium magnets are used in the design, capable of holding the level even in the “on the ceiling” position. At the same time, this function is far from always relevant, so the same model can be produced in two versions — with and without a magnetic base.
— Impact site. The ability to use the level for impact work — in other words, to knock directly on it, transferring the blow to the material under the level. This function can be very useful when laying tiles, bricks, etc. — it allows you to trim the material with the help of blows and at the same time control the quality of laying with the help of a level. Usually, the shock platform has the form of a sloping surface on one side of the level; often it is supplemented with a rubber lining that reduces wear. In the absence of such a platform, it is impossible to knock on the instrument — you can damage it.
— Digital display. The presence of a digital display in the tool design. This function is not required for classic levels — bubble capsules are enough to control the horizontal / vertical. But for a goniometer (see "Type"), the display will be useful — it affects the total cost, but provides much greater accuracy than a mechanical scale. Inclinometers, by definition, have this function. Please note that the display requires batteries of one type or another (see "Power").
— Backlight. The presence of illumination in the design of the level. It can be both for the digital display (see above) installed in the instrument, and for capsules. This feature makes level operation independent of ambient light and will be especially useful in low light conditions — by turning on the backlight, you can easily see the values in twilight or even in complete darkness.
— Extendable design. The ability to lay out the tool, increasing its working length. This feature is found mainly in "large-caliber" levels with a working length of 3 m or more. On the one hand, in some situations, such a length is indispensable from a practical point of view, while making a clumsy tool of this size does not make sense — the design would be too bulky and inconvenient to store and transport. Folding allows you to significantly reduce the length — usually, by more than a third, for example, from 320 cm to 180 cm. On the other hand, an additional mechanism adversely affects the accuracy of measurements — often when unfolded, it is lower than when folded; and as the moving parts wear and loosen, the error increases even more. Therefore, manufacturers try to do without a sliding structure as far as possible and provide it only when it is practically impossible to do without it.
— Laser pointer. The presence of a laser pointer in the tool design. This function is found exclusively in inclinometers — the laser beam plays the role of continuing the tool, increasing the working length to 20 – 30 m (see "Measurement range"). This provides many additional possibilities: for example, you can determine the attachment point of a long inclined beam by installing an inclinometer at the location of the beam base and tilting it to the required angle — a laser mark will indicate the attachment point of the upper end of the beam.