The distance measurements They are common in activities covered by areas such as construction, surveying, surveying, road works or real estate, particularly in gas installations, plumbing, air conditioning and water tanks, masonry, carpentry, locksmithing, painting and a long etcetera, which also includes DIY work at home. Many who take measurements may find the idea of replacing their valuable tape measure, odometer, or even meter, with electronic instruments challenging.
However, when it comes to meeting the requirements of speed, precision, security, versatility, convenience Y functionalityPresent in many of the activities that involve frequent measurements, it is clear that the old traditional instruments have the upper hand. Not to mention if a small electronic device the size and weight of a cell phone is also capable of add and subtract lengths, calculate areas and volumes, perform complicated triangulation operations, store data Y export them to our computer or tablet via Bluetooth and / or USB, all in a matter of seconds, in an extremely simple way and with more than optimal results.
Why do we say in a simple way? Because we simply point the EDM at the object whose magnitude we want to measure, we press a button and that’s it! We can immediately read that distance on the screen of the device, with astonishing precision.
Therefore, with these benefits, would we continue to resist change? Probably not. Let’s meet then, at laser distance meter, or laser distance meter, and everything it offers us without having to shell out a fortune.
How does the laser distance meter work?
The tiny ones laser distance meters Today they are derived from much larger electronic instruments that appeared on the market some 65 years ago, precisely to overcome the difficulties posed by accurately measuring long distances.
The foundation that governs the operation of electronic distance measuring instruments consists of three basic steps:
- Emission of a wave which, depending on the instrument, can be one of the following types: microwave oven, ultrasound, infrared or To be;
- Time measurement how long it takes for that wave to go from the emitting instrument to the object whose distance we want to measure and to return to the emitting instrument, and
- Conversion of that time in distance.
Of the four types available, the laser wave based meters They are not only the most modern, but also those with the best precision, those that measure the greatest distances (up to 250 meters, depending on the model and manufacturer) and those that offer a wider range of features, thus offsetting their price somewhat more. elevated relative to others.
With a laser distance meter we should NOT worry about:
- The presence of obstacles, such as trees, bushes, cables, pipes or furniture in the path that we want to measure
- The solidity, texture or inclination of the object to be measured
- The degree of brightness of the environment or the time of day to take a measurement outdoors
- Weather conditions (rain, wind, snow, etc.) at the time of measurement
- Climbing steep and dangerous stairs or slopes to measure a distance to the roof or terrace of a multi-story building
- Enlist the help of another person to hold the other end of a tape measure
- Make annotations and calculations
If there is a line of sight to our objective and it is within the range of the device, we can always know exactly how far it is. We can even measure the width or height of a building from the sidewalk or from a reasonable distance.
Parts that make up a Laser Distance Meter
With a design very similar to a cell phone or pocket calculator, the laser distance meters They have an appearance that varies by manufacturer, but generally contains the components shown in the following figure.
Most models also incorporate other elements on the sides of the device, such as a spirit level, another button for measurement, a strap and a thread to facilitate mounting the device on a tripod.
Depending on the manufacturer and the model, the laser distance meters can work with common AAA batteries, with 9 V batteries or with lithium batteries, where in each case an increasing autonomy is obtained. In other words, while a set of two AAA batteries can ensure about 3,000 measurements, 9 V batteries exceed 5,000 and lithium batteries, rechargeable via micro-USB connection, guarantee about 25,000 measurements per charge.
Many meters also include protection against dust, water, and mud, so they can be used safely in harsh weather or work conditions.
All laser distance meters offer at least direct length measurement. Those of medium and high range also incorporate the indirect measurement of lengths and heights. Let’s see briefly what each of these measurements consists of.
1) Direct length measurement
It is simply a matter of placing the device at one end of the object to be measured and pointing the laser beam towards the other end of that object. Thus, we will instantly obtain the distance reading on the screen.
As we see in the figure, we can measure the dimensions of a room by placing the meter in different positions or we can also measure the distance that an object, such as a tree, is from us. It is important, to obtain accurate measurements, take into account the measurement reference, that is, from which part of the EDM the measurement is calculated: if it is from the base (generally, the default option in most meters), from the middle part (for example, if we use a tripod) or from the upper part. To do this, we must configure function 11 in Figure 1, the detail of which we see below.
With these simple measurements we can also obtain the measurements of the perimeter (using the sum of lengths function, key 4 of Figure 1), the area and the volume (key 3) of a room.
2) Indirect measurement of lengths and heights
Measurements cannot always be as straightforward as the ones we have just seen, especially outdoors. In this case, meters are used that have the indirect measurement function, which is based on direct measurements like the ones we have just seen, but subjected to triangulation operations to give us the magnitude we want. Triangulation applies the well-known Pythagorean theorem for a right triangle, that is, one that contains an angle of 90º, where “the square of the hypotenuse is equal to the sum of the squares of the legs”.
To do this, again depending on the model, EDMs offer three possibilities, in all of which there must be a 90º angle between one of the measurements and the distance to be measured. This implies that the location of the meter and therefore ours (or the tripod) is important. Let’s see what those possibilities are:
to) Two point measurement
If, for example, we want to measure the length 3 of the house in the figure above, we must:
- stand and align with one of the corners of the house
- carry out, without moving, two measurements: one represented by line 1 and the other by line 2 of the figure. The display will show length 3.
If we want to measure the height 3 of each, we must:
- place the meter on the floor
- carry out, without moving, two measurements: one represented by line 1 and the other by line 2 of the figure. The display will show height 3.
b) Three-point measurement
This possibility provides more accurate measurements.
If we want to measure the length 4 of the house in the figure above, we must:
- stand anywhere between the extremes to be measured
- carry out, without moving, three measurements: one represented by line 1, another by line 2 (perpendicular to the house) and another by line 3 of the figure. The display will show length 4.
If we want to measure the height 4 of the house in the figure above, we must proceed in a similar way to that indicated above.
c) Double height measurement
This possibility allows us to make more complicated measurements, for example, the distance between A and B in the figure below.
To do this, always from the same point, we measure distance 1 to point A, then distance 2 to point B and finally the perpendicular distance 3 that separates us from the building.
As we can see, the benefits offered by a practical laser distance meter are numerous and fundamentally accurate. In fact, the market offers a wide variety of devices that adapt to all needs and possibilities, which is why it is important to make a good choice. We will deal with this in the next article.
In the video below we will be able to appreciate some of the functionalities, which correspond to the Bosch GLM 80 Laser Distance Meter