How and what to measure with a laser rangefinder (tape measure)

Types of rangefinders

Based on the principle of operation, laser rangefinders are divided into phase and pulse.

Phase meters

Phase rangefinders do not have a very long range, but they are much more accurate due to the principle of their operation and are cheaper due to the fact that they do not have an expensive, ultra-precise timer built into them.

The phase rangefinder works at short distances, but has good accuracy and a low price

The operating principle of rangefinders of this type is that a laser wave is sent to an object with one phase, and when reflected, returns with another. Having calculated the phase shift, the device determines the distance to the object. Thanks to this operating principle, phase rangefinder measurements are highly accurate. If it is necessary to work at distances exceeding the emitted wavelength, the device sends a signal several times, changing the modulation frequency. The device's processor then determines the exact distance to the target by solving a system of linear equations.

Pulse meters

A pulse rangefinder consists of a radiation detector and a pulsed laser. It calculates the distance to an object by multiplying the travel time of the beam by the speed of light. Pulse meters operate over much greater distances than phase meters due to the higher power of the emitted pulse. Such rangefinders are often used for military sights.

The device of a compact laser construction rangefinder

Despite its apparent simplicity, a laser ruler is a complex engineering device. The laser rangefinder device consists of the following components:

Scheme of laser rangefinder operation

Emitter - it generates a beam and sends it to the desired point.
Reflector - it is necessary to receive the beam reflected from the object.
Microprocessor to perform the necessary calculations.
A pre-installed program necessary for processing the data obtained during measurements.
A sight that allows you to direct the beam to the desired location.
A level with which the device can be strictly aligned in a horizontal or vertical plane.

Additional functions

The microelectronics used in laser rangefinders allows not only direct measurements. Many devices of this type have some additional functions, which include:

Continuous measurement function. When operating in normal mode, the rangefinder, when you press a button on the remote control, records the result and displays it on the monitor. But quite often, there is a need to constantly measure the distance, for example, from a wall to a future partition. To do this, the device is switched to continuous measurement mode. In this mode of operation, the device independently takes measurements at a certain frequency and displays their results on the monitor. The measurement takes place in real time.

Determination of the greatest and smallest distance. This function is useful when determining the diagonal in a room. The fact is that it is not so easy to measure it and you can simply miss when directing the laser beam and, as a result, inaccurate results will be obtained. After setting the minimum distance on the device, it will record only those measurements that are greater than the set one.

Laser rangefinders for work indoors or at short distances

All rangefinders can be divided into two large groups. Some are used for internal work, others for external work. The measurement range of rangefinders that are intended for indoor measurements usually does not exceed 100 meters.

Laser rangefinder for indoor use

For such work, rangefinders that use both operating principles can be used.

Types of rangefinders

Based on the principle of operation, laser rangefinders are divided into phase and pulse.

Phase meters

The phase rangefinder works at short distances, but has good accuracy and a low price

Pulse meters

Comparison of the operating principles of pulse and phase meters

A phase rangefinder uses a modulated light signal to measure distance, while a pulse rangefinder uses a light pulse.
Pulse rangefinders measure much longer distances than phase ones, since the power of the pulses they send is much greater.
The pulse distance measurement method is less accurate than the phase difference method. But thanks to modern signal processing techniques in pulse rangefinders, this difference becomes less significant.
The size of the reflected laser dot becomes larger with increasing distance. This is true for both measurement principles, although the deviation of the laser from the reflection point is different because the size and shape of the laser spot is different.
The phase and pulse principles of operation also differ in sensitivity to signal interruption. When operating under the influence of certain external factors (in traffic, in bad weather conditions), a phase rangefinder will perform worse than a pulse rangefinder.

Phase rangefinders

For a phase range finder to work, a sinusoidal principle is used when the phases of the sent and reflected signal are compared. When the result of such measurements is obtained, it is a distance. These roulettes are distinguished by a high level of accuracy, and they are also expensive.

There are different operating modes for these devices:

Standard,
Scanning,
For adverse operating conditions,
Mirrored.

How to choose a rangefinder: recommendations

Electro-optical rangefinder.

Before purchasing a rangefinder device, you need to decide on the upcoming work, that is, for what purpose it is needed. The more functions a device has, the more it will cost.

Points to consider before choosing:

Classification.

Similar devices are:

household;
professional.

If the device is purchased for interior decoration of apartments, then a simple household device will be suitable for these purposes. If you have to work under more severe conditions and on complex construction sites, then you need to think about professional equipment. But the price of professional devices is much higher. It also happens that some household rangefinders may be equipped with additional functions.

Measuring range.

Block diagram of a pulse laser rangefinder.

Modern laser measuring instruments can have a beam range of up to 200 m

When purchasing devices with a maximum measurement range, you need to pay attention to the device for installing a tripod, since when taking measurements at long distances, you need to have a tripod. If the device is used for the construction of a country house or on small construction sites, it is enough to use a rangefinder with a range of up to 50 m

Rangefinder accuracy.

Basically, all laser rangefinders have measurement accuracy with an error of 1.5 to 2 mm, which solves problems in domestic and professional settings.

Manufacturer.

The quality of rangefinders also directly depends on the manufacturer. The best companies producing rangefinders are considered to be BOSH and Stabila. As a rule, devices from European manufacturers are much more expensive than Chinese-made products, but the quality of Chinese ones is much inferior.

Warranty service.

Any well-known company provides a warranty card for its equipment, granting the right to service. In normal cases, the warranty is given for 1-2 years for household laser devices and up to 3 years for professional equipment. When purchasing a rangefinder, you need to find out whether there is a center for servicing the equipment of a particular company.

Design and ease of use.

When selecting a laser device, you need to hold it in your hands. It should be comfortable, light and not fall out of your hands. The smaller the dimensions of the device, the more convenient it is to use, since it can even be placed in a pocket. For ease of use of the rangefinder, many manufacturers equip its body with rubber parts.

Functionality.

Conclusion

Mileseey X5 delivery set

Mileseey X5 is an excellent laser rangefinder from China. Manufactured by a company that professionally deals with measuring instruments and has established itself as a reliable and high-quality manufacturer. The device can easily compete with brands such as Bosch, Makita or DeWALT. During the sales period, the rangefinder version 40-60m can be purchased for 700-800 rubles, which makes its purchase even more attractive.

Examples of models from different manufacturers

For home use, you should not buy overly advanced laser measuring tapes. How to choose a decent tool without spending extra money can be seen using the most popular models as an example:

Bosch DLE has several modifications with similar characteristics. The distance to the object is a maximum of 40 meters. The error is 1.5 millimeters and the temperature range is from -10 to + 50 degrees. They have no additional functions and are not bad for home use. The lack of backlight limits the device's capabilities to bright rooms.
The Leica DISTO D2 operates at a range of up to 100 meters and has additional functions. It can transmit data via Bluetooth, is small in size and is powered by two batteries. The measurement accuracy is 1.5 millimeters. All this is placed in a shockproof and dustproof case. The disadvantage is the price and work exclusively with iOS.
MAKITA LD 060P is quite popular among buyers. It has good functionality and an affordable price. The advantages include a large screen and large symbols on it. The technical characteristics do not stand out in any way, but recently defective products have come across.
Agatec Agatape is suitable even for small construction sites. Range up to 60 meters; additional functions include a stopwatch.

Criterias of choice

It doesn’t matter whether you are looking for a model from a well-known manufacturer, or trying to purchase a budget analogue. When choosing, you will still be guided by the purpose for which the rangefinder is purchased, as well as the regularity of use. There is no need to purchase an expensive model if you do not plan to use it regularly.

Those who are planning to choose a laser tape measure should pay attention to the class of the laser, which directly affects the measurement distance. There are three classes:

Class 2. They are found in rangefinders operating at distances up to 70 m. They are considered safe; a beam accidentally entering the eyes will not harm the retina.
Class 2M. The beam power is higher, it works at medium distances and can damage the retina, but it makes it easier to take measurements outdoors, especially in cloudy weather.
Class 3R. They work with rangefinders operating at 300-500 m and require the use of safety glasses.

Laser power affects the measurement range Source mosoblzhilservice.rf

Additional functions and capabilities of laser roulettes

The main functions of laser tape measures are to calculate distances and sizes, angles and hypotenuses, as well as the area and volume of measured objects. All this can be immediately calculated directly on the device display, without making calculations on a calculator. And due to the fact that the device has a built-in memory, you can save calculations in it (the number of stored readings may differ in different models). In addition to various calculations, rangefinders can have the following additional functions and components:

Auto power off. The function will automatically turn off the device if it is in standby mode for a long time, that is, it is not used. The shutdown time varies between models, so you should check the specific numbers directly with the device manufacturer.
Holder or tripod. The first structural element is necessary to secure the device to a wall, window sill, table and other objects. If you do mostly indoor work, then you will need a holder. A tripod or tripod is convenient for outdoor measurements. Leica Disto S910 Pro Pack is an example of a laser tape measure with a complete set including holder and tripod. This professional, expensive device is definitely not suitable for everyone, but it has a full range of functions and components that are needed for measurements, both in rooms and in open areas.

Bluetooth. A device with Bluetooth function can connect to a smartphone or tablet and transmit readings to it. Thanks to this, you can save all calculations in the phone’s memory, for example, in a created estimate. Of the good devices for the home with excellent accuracy and Bluetooth, we can recommend the SNDWAY SW-S50.

Varieties and their applications

The question of how to choose a laser rangefinder is of interest to people who are faced with the variety of offers for the first time. You can cut off a significant part of them if you formulate the boundaries of use for yourself. According to this principle, laser roulettes are divided into two types:

Household. The models are relatively cheap, but this does not affect the accuracy. They will help during renovations or construction. Additionally, they are equipped with a calculator for calculating the area, and a small memory for saving measurement results.
Professional. Such instruments have an expanded range of functions, the ability to measure long distances (50-100 m or more), expanded memory, a high degree of protection from dust and moisture, and work with Bluetooth for data transfer. Many models are threaded and can be mounted on a tripod, increasing measurement accuracy.

Rangefinders have become indispensable assistants in various fields of activity; they are used in the following areas:

Excavation work during construction and laying communications.
Construction and finishing work, including marking of lumber.

Many models will help you calculate the amount of materials Source pirometr.com.ua

Geodetic work, land surveying.
Installation work during the construction of structures and communications.
Design of premises and landscape, development of cabinet furniture.
Applied tasks: hunting, navigation, control (inspection work), military affairs.

To solve design or land management problems, you need tools with a different set of parameters, and it is important to understand which of them are basic and which are secondary.

See also: Catalog of companies that specialize in the reconstruction and rebuilding of houses

Peculiarities

When working with a laser rangefinder, it is advisable to take into account some features of working with this device.

Rangefinders have the ability to take measurements at different distances and with a certain error. Thus, the maximum distance can range from 60 to 200 meters, with an error of 5 cm. These data are indicated in the product passport. Most rangefinder models operate within the range from – 10 to + 50 degrees.

When operating the device outdoors, you must remember that weather conditions play an important role. Performance may be reduced in both poor and sunny weather.

When taking measurements, it is necessary to eliminate obstacles that may arise between the device and the object, this could be foliage, glass, etc.

The practice of using laser measuring instruments has led to the emergence of certain operating rules. For example, the measurement result will be distorted if the beam is directed at a highly reflective surface (mirror, foil). The result will not be entirely correct if the beam is directed at an object with low reflectivity (tar paper).

To obtain extremely accurate results, use a special device with a reflective surface.

During operation, it is necessary to constantly monitor the condition of the batteries. Weak current sources also negatively affect measurement results.

It is advisable to use a tripod when taking measurements. In this case, the measurement accuracy will be increased.

How to use a laser tape measure

Using a laser rangefinder in practice is a fairly simple task. To perform a measurement, it is enough to set it at the starting point, point it at the object to which it is necessary to measure and activate the device. It must be remembered that to increase accuracy it is advisable to use a tripod, this is especially true when measuring large quantities.

How to use a laser tape measure

That is, measurements can be carried out, perhaps even by one person without the involvement of assistants.

Comparison table of the best laser rangefinders

Name	Main characteristics	Price
Sndway	The operating distance is 40 meters, the error is no more than 2 mm, it can store up to 30 different values in memory, there is a function for calculating height using the Pythagorean formula.	₽ 1864 Buy
Leica	Withstands temperatures down to -25°C., operating distance is 40 meters, error is 2 mm, the device works with Bluetooth and mobile OS.	₽ 6990Buy
BOSCH	There is a color display IPS display, operates at a distance of 120 meters with an error of 1.5 mm and 0.2° when measuring angles, connects via Bluetooth or USB, is protected from dust and splashes according to the IP54 standard.	₽ 15183 Buy
Elitech	The measuring distance is 40 meters with an error of 2 mm, measures angles up to 60°, and has a monochrome display.	₽ 2213 Buy
Makita	The operating distance is 80 meters, it measures the depth and volume of an object in real time using the Pythagorean formula, there is a cover that protects the body of the IP54 standard.	₽ 11710Buy

Device characteristics

Regardless of what additional options the laser rangefinder is equipped with, it has the following characteristics:

Measurement range (shows the maximum distance at which the device can measure the parameters of an object with the accuracy declared by the manufacturer. For modern models, this figure reaches 100 m).
Accuracy (permissible measurement error. Usually within 3mm).
Nutrition . Usually carried out from AA or AAA elements (so-called “finger” or “pinky” batteries). Some models are powered by batteries or non-standard types of batteries, but it is better to choose a device with classic batteries, which can be easily found in the store.
Weight . Modern compact rangefinders weigh up to 150 grams. Heavier models are inconvenient to use, especially if you have to work with the device constantly.

Additional functions

In addition to the main function (distance measurement), modern models can be equipped with options that allow them to solve many other problems: calculate volume and area, perform mathematical operations, etc.
The most popular add-ons are:

Level (with its help you can determine the deviations of planes vertically and horizontally).
Goniometer (together with the level allows you to make several measurements simultaneously).
Protection from dust and moisture . Rangefinders are precision electronic devices. If dust or moisture gets inside, it may fail. Almost all modern models are equipped with protected cases. However, if you plan to operate the device in unfavorable conditions, it is recommended to choose an option with increased protection. Additionally, you can purchase a special case.
Backlight . Even on expensive models with many additional options, you can sometimes find a monochrome display and a non-backlit keyboard. Such devices are not very convenient to use. It is better to choose a device with activated or constant backlighting and a color display.
A rangefinder equipped with this function can be connected to a smartphone, tablet or laptop to save, analyze and transfer data. If you perform all these steps manually, the pace of work will decrease significantly.

Operating principles of laser rangefinders.

According to the method of using the properties of the laser beam, devices are divided into pulse and phase.

The pulse rangefinder device is based on measuring the time it takes for a laser beam to travel from the laser generator to the reflector (object) and back.

Pulse laser rangefinders have high power, range of use, secrecy due to short-term use and imperceptibility, for the human eye, of a beam operating in the infrared range.

All these excellent qualities, just in time, meet the needs and demands of military artillerymen, aviation, navy, etc.

Phase laser rangefinders calculate the distance to an object based on the phase shift of the modulated backlight frequency. As unnecessary, they do not have a reflected signal timer, which makes them low in cost.

The range of use of phase laser rangefinders is small (up to a kilometer), so their area of application is domestic needs and rangefinders for small arms.

Set of laser rangefinder functions

Laser rangefinder KRAFTOOL Laserkraft, 34760_z01 With all the variety of choice of laser rangefinders, simple and inexpensive models have approximately the same capabilities:

addition, subtraction;
calculation of area and volume;
simple Pythagoras;
frontal reference point;
starting point from the base;
built-in protractor;
folding bracket (for measurements in hard-to-reach places).

More expensive models have wider professional functionality:

complex Pythagoras;
continuous measurements;
specified segments;
timer;
viewfinder (for outdoor work and long distances);
wide-range inclinometer (from 45 to 360 degrees);
Bluetooth, USB

Accuracy of laser rangefinders

Modern models have measurement accuracy with an error of 1.5 to 3 millimeters (this is believed to be sufficient for outdoor and indoor work). High-precision laser rangefinders, when operating up to 300 meters, determine the distance with an accuracy of +/- 1 millimeter (as the manufacturers claim).

When carrying out high-precision measuring work, it is recommended to use a tripod or use laser rangefinders from a stationary surface to avoid the influence of hand vibration on the accuracy of measurements.

Functional

In the era of technological progress, it is naive to believe that the capabilities of a laser rangefinder will be limited to just measuring distance. Even relatively inexpensive devices include a decent arsenal of formulas and modules that allow you to determine the perimeter, area and even volume of the objects under study. Simple devices with a single measurement function are also found, but even in the most budget segment they are becoming increasingly rare. The greatest number of possibilities is concentrated in professional rangefinders, which represent a concentrated storehouse of theorems for a variety of calculations. Further details about each function specifically.

Area and volume
can be calculated in the standard way, by measuring each face by applying a device, or from one point from the side. The function is useful for finishing work, as it greatly facilitates and speeds up the calculation of the amount of material required.

The level
is useful for a wide variety of construction, installation and repair work. The equipment can be designed as a regular spirit level mounted on the instrument body or as an internal module that displays the degree of angle on the display.

Folding-type brackets
allow diagonal measurements from corners where a tight fit of the rangefinder body is not possible. In some models, this function is performed by retractable pins located inside the housing.

Saving data
makes it much easier to work with large projects, eliminating the need to keep notes in a notepad. The ability, at any time, to raise a dozen or two old measurements can help out both at the workplace and in a building materials store.

Data transfer to a PC or smartphone
is mainly carried out via cable, but more and more models are beginning to be equipped with a Bluetooth module.
Measurements can be transmitted in standard text formats, or loaded into special programs, where they can be converted into a full-fledged project drawing. Continuous measurement
turns the rangefinder into a real laser tape measure, updating the distance to the target in real time. The function makes it easy to measure parts of the required length and helps to check for unevenness in the coating.

The viewfinder
is a magnifying optic for accurately aiming the beam at distances of more than 15 meters.
In professional models, the function looks like a camera that displays an image with an aiming point in the middle. Measuring height
allows you to get accurate data about the size of a house or the length of a tree when measured from the side. It is enough to measure the distance from the rangefinder to the base, and to the end point. Based on the received data and angles, the device calculates the height. For maximum accuracy, it is recommended to make such measurements on a stationary tripod using a viewfinder.

Xiaomi Duka LS-P Laser Range Finder

The next hero of our TOP is Xiaomi Duka LS-P Laser Range Finder.

This rangefinder is suitable for home use and lovers of minimalism. The device is very compact, fits easily into any pocket and weighs only 28 grams. Its body is made of aluminum-magnesium alloy and ABS plastic, which is resistant to damage and has a rough coating to prevent it from slipping out of your hands.

This device is designed to measure lengths up to 40 meters and does it quite accurately. The error is no more than 2 mm. It can also be used to measure angles, find area and volume. The control is extremely simple, since the device has only 2 buttons. Moreover, the device allows you to store several recent measurements in memory.

It is powered by a built-in battery, the capacity of which is enough for approximately 350 measurements. And you can charge the device using a regular USB cable, which is used to charge smartphones and other gadgets.

One of the disadvantages of the rangefinder is that the screen is too small. The numbers on it are clear, but small. People with poor vision will find it difficult to view them. And for professionals, it will be inconvenient to constantly peer at the measurement results on a small screen. But for infrequent use at home, such a rangefinder will be an excellent purchase.

Length measurement range: up to 40 m.
Length measurement accuracy: ±2 mm.
Laser class: 2.
Power: battery.
Dimensions: 86 x 22 x 11 mm.
Weight: 28 g.

Content

On sale, there are a large number of cheap sensors - rangefinders, including ultrasonic and infrared. All of these devices work well, but due to their significant weight, they are not suitable for flying robots. A miniature robotic helicopter, for example, can carry about 100 g of payload. This makes it possible to use machine vision to find obstacles and avoid collisions with them, using webcams (or other miniature, wireless cameras connected to a computer via USB). Better yet, install two cameras, which will provide the robot with stereo vision, thus, thanks to information about the depth of the image, it will improve obstacle avoidance. The disadvantage of this idea is the relatively large weight of the camera.

Types and principle of operation of the tool ↑

Despite the unifying concept of "rangefinder", each individual type calculates distance using different methods. Highlight:

ultrasonic;
phase laser;
pulse laser;
optic;
optical filament types.

The roughest active type for measuring distance is an ultrasonic device. Its work is based on the principle of echo location, which is used even by some animals, for example, dolphins. The device creates a sound pulse and picks up an echo - sound waves that are reflected from an object.

For measurement accuracy, high frequency sound is used - 40 kHz. Since the speed of sound is known and the time it travels is easy to measure, all that remains is to calculate the distance, which is what an ultrasonic rangefinder does.

A simple model based on an ultrasonic sensor

If the same method is applied with a light pulse, the result is an accurate pulse-type laser rangefinder. The fact is that the speed of light is so high (300,000 km/s) that for small distances that are measured in construction (20, 30, 50 m), we are talking about fractions of nanoseconds. It is very difficult to measure time with such precision.

The main advantage of such a device is that it sends short pulses of light rather than a constant beam. This means that a high power laser can be used. Such a powerful impulse can easily “fly” back and forth over a distance of 100 km in a fraction of a second. This property is most often used in the military industry, and the device itself is much more expensive than its analogues.

How does a laser pulse work?

The operating principle of a phase-type laser rangefinder is based on comparing and determining the phase shift of a light wave. The device generates a light beam in the infrared spectrum. The beam moves at a known speed to the measurement target, is reflected and returns. The tool compares the phase of the light wave at the beginning of the movement and at the end. The measurement is taken twice, after which the device displays the result in meters.

One of the advantages of this type of distance meters is the price. They are much cheaper than pulse ones, because there is no need to equip a laser tape measure with an ultra-precise and expensive stopwatch. In addition, with the phase method the error is no more than half a phase, that is, less than a millimeter. This is an amazing result, but this device also has disadvantages.

Phase laser model

Since you have to shine not in short pulses, but constantly throughout the measurement, it will not be possible to install a powerful laser. This means that the device is not used over long distances. However, for construction purposes its range is more than enough.

Optical rangefinders are mainly used in geodesy, topographical work, navigation, and photography. It works according to the passive type, based on the Pythagorean theorem. The operating principle of such a device is difficult to describe with your fingers.

Military rangefinder

It is based on constructing an isosceles (for stereoscopic devices with two eyepieces) or right-angled (for monocular) triangle and mathematically calculating its height. The vertex of the triangle is the point to which the distance needs to be measured. Aiming is done manually.

In some rangefinders you need to compare two parts of the image for adjustment, in others you need to eliminate ghosting in the image. One way or another, the main sensor is the human eye, so error is inevitable.

Device diagram

A thread rangefinder is another optical device for measuring the distance to an object. It also works based on geometric calculations. To measure range, you need a special rangefinder rod - a long “ruler” with markings. The distance between the divisions is 2 cm. The rod is installed at the point to which the distance needs to be measured.

Thin threads are stretched inside the telescope. The rangefinder and the staff are set strictly level, so that the zero mark of both is at the same height. Next, the surveyor looks into the lens and counts how many 2 cm divisions are placed between the stretched threads. Thus, a triangle is constructed with the vertex at the focus of the instrument lenses.

The length of the height of this triangle + the focal length will be equal to the distance between the selected points. This type of rangefinder is often found in theodolites of different models.

What the surveyor sees through the peephole

Budget laser tape measure (rangefinder) Lomvum LV40 (LV-B) with bubble levels.

Hi all! Today I’ll tell you about an inexpensive and simple laser rangefinder (tape measure) from Lomvum, capable of taking measurements at a distance from 5 centimeters to 45 meters (instead of the stated 20cm-40m). The device also has two bubble levels, calibration functions, measuring area, volume, according to the Pythagorean theorem, sound signal, etc. I’ll say right away that there are no problems with accuracy, everything is at the proper level! This is already my second acquaintance with this kind of devices. Before this, for a long time I used the same budget rangefinder for 40 meters, but from a different brand, from Atorch. I already had a review of it. I was happy with everything about it, and I bought a new one only because they asked me to sell the old one. I chose this model based primarily on the low price, roughly similar menu to the old model, and the bright orange color of the body. Still, just black easily blends in and gets lost among the rest of the tools, while a bright color will immediately catch your eye. This is exactly what is needed in this case, when the device needs to be found immediately, and not searched for and wasted time on it. The manufacturer has two very similar visually models. One is more expensive, without physical levels, but with digital ones, with a large number of memory cells (60 instead of 20). These additional parameters were not very important to me, I took the one that was cheaper - LV-B. Visual differences and differences in functionality can be seen in the photo below.

Specifications

Purchase

Packaging and appearance
The device is supplied either in a small branded box made of thick cardboard, or simply in an air bag. I didn’t need the box; it would have been immediately thrown away anyway.

The contents were carefully packed and arrived safe and sound.

The delivery set includes: • laser rangefinder (1 pc.) • reflective plate (1 pc.) • transport bag (case) (1 pc.) • lanyard for hanging (1 pc.) • user manual (1 pc.)

Instructions in English, quite detailed with illustrations. I think it can help out in a situation when you have difficulty finding and setting up a particular function.

The reflective plate can be found with many modern rangefinder models. It is used in situations where the surface, the distance to which needs to be measured, is mirrored or completely transparent. We must not forget to take into account the thickness of the plate itself, in this case it is equal to 1.1 mm. In fact, I have not yet had the opportunity to use it, although it was already included with the old device. It seems to me that it will not be of much use because the size is too small.

The seller also included a case for carrying and storage. It is made of thin and soft material. If necessary, it can be hung on a belt; for this purpose, there is a corresponding mount on the back side.

Let's take a look at the device itself. It is made outwardly in almost the same form as a large number of the same models from other manufacturers. This is a small rectangle with the following dimensions: length - 115.3 mm, width - 52 mm and thickness - 28.8 mm. The body is made of matte plastic, the front and back sides of which are bright orange, and the ends are matte black. It is absolutely not worth dropping or immersing in water; the case is not sealed and has no protection against water penetration. On the front side of the device there is an LCD monochrome display, a block of control buttons and two bubble levels. Above the display there is a company logo, in my case it says Lomvum, but there are copies where another brand is indicated - Zeast Mini.

Place for attaching a lanyard in the lower right corner. I thought there would be problems with its installation, but nothing happened.

There is a sticker on the back with brief technical specifications. As we see before us is the LV40 model with a measurement range from 0.2 to 40m and an accuracy of +- 2mm.

Just below is the battery compartment. Both regular mini AAA 1.5V batteries and batteries of the same size Ni-Mh with a voltage of 1.2V are suitable. Roulette works fine with both types.

Serrated ends for better grip. They are made of regular rough plastic, not soft-touch.

I don’t really know much about the circuitry of rangefinders, so I’ll leave the photos of the insides without comment.

Parsing

Control

Buttons and functions: 1. Long press to turn on the device, short press to measure distance 2. Area/volume measurement 3. Measurement with or without body length 4. Memory button 5. LCD display 6. Continuous measurement: max/min 7. Add/subtract 8. Switch volume/unit m/in/ft 9. Cancel/Back/Off 10. Vertical and horizontal bubble level

Features include the following: • measure distance to an object, calculate area and volume, • support measurements in meters, inches and feet, • single or continuous measurement, • indirect measurement function using the Pythagorean theorem • track maximum and minimum distances on the screen • function simple calculator (+, -, addition or subtraction) • measurement with or without case length, • 20-cell memory, • laser pointer for easy aiming, • large backlit LCD display with 4 text lines, • sound indicator, • battery charge indicator, • intelligent computing.

I will not talk in detail about each function, buttons and their capabilities. I think that after holding the device in my hands for a couple of minutes, everything will become clear. I’d rather pay attention to the hidden and not obvious section of the menu. Getting into it turned out to be not so easy. I was unable to get to the desired menu by poking and pressing different combinations of buttons, so I contacted the seller. He also did not immediately understand what I wanted from him, but in the end the issue was resolved positively. The device has a hidden calibration menu. To enter it, you need to simultaneously hold down the three buttons marked below in the photo and, without releasing them, also hold down the fourth. In a couple of seconds we will see the hidden section. You can calibrate within the range from -10 mm to + 10 mm. The default value is set to +1mm. Looking ahead, I’ll say that I changed it to +3mm, i.e. added another 2mm. Practice tests

The device has a nice bright display with normal viewing angles. Readability remains at the proper level even in bright daylight. The backlight is white and turns off automatically after 5 seconds during inactivity. In fact, there is nothing unusual here; similar screens are installed in many models. Only displays with color inversion will be inferior in readability, i.e. where the background is black and the numbers are white. First of all, I decided to check the measurements at a short distance; for this I took an ordinary ruler as a standard. The device begins to measure the distance not from 20 cm as stated by the manufacturer, but from 5 cm, and it does this more or less adequately. I made a comparison at a distance of 5cm, 20cm and 30cm. And as you can see, in each case the rangefinder showed 2mm less than it actually is. This was before calibration. After making a small correction, the results no longer differed from those measured with a ruler. Of course, I cannot be 100% sure of the accuracy of the measurements of this (not the cheapest, by the way) ruler, but it is necessary to compare it with something.

Next, I increased the measured distance first to 1 m, and then gradually to 5 m. This time I compared the results with a regular roulette. This time there were deviations again, but not in all cases. For example, at a distance of 1 m, both laser and regular tape measures showed the same thing. But at 3m and 5m, the laser output was 2mm less. I took these measurements before calibration. After it, the values completely coincided with those measured with a regular tape measure. In principle, everything can be seen in the comparative photos below.

There are no problems with response indoors. The device takes measurements almost always without error. But in bright sunlight, the percentage of successful measurements is of course lower. Being on the street at a great distance, you can only see the laser point with your eyes in the evening, when the sun is already going below the horizon. I took some measurements outdoors. I noticed that the greater the distance to the object, the slower the measurement occurs. This is a feature, I don’t know whether it is inherent in all rangefinders or not.

The maximum distance that was measured was 45 meters. The device no longer sees this and displays error 261. The test itself was carried out not at night, but in the evening. The laser point was very difficult to see at such a distance.

In addition to simply measuring the distance, you can also determine the area of the room. For example, in the photo below this is the area of my garage.

Its volume. Also make measurements using the Pythagorean theorem. In this case, the accuracy will depend on how level we hold the rangefinder at the moment of fixing the distance. It’s a pity that there is no hole for a tripod, then it would greatly simplify the task. I'm happy with the device. It performs its main task, measuring distance. It does this with an acceptable error, but, if necessary, it can be calibrated against a standard (if you find one). By the way, when the rangefinder is turned off, it does not consume anything, so the batteries will not discharge quickly. In standby mode, consumption is approximately 0.1A, and during measurements 0.2A.

What is a laser rangefinder?

To accurately and quickly measure relatively short distances, a household laser rangefinder is used, the characteristics of which differ from those of professional devices. The device is a plastic case in which a light signal emitter and its receiver are built-in. A special display instantly displays information about the size of the desired object or the distance of objects from each other.

More complex models are equipped with a microprocessor that is capable of performing some calculations. A laser construction rangefinder can calculate:

square;
volume;
angular values;
unknown side of the triangle;
divide the distance into an equal number of segments or footage, subject to a certain proportion;
all found parameters can be recorded on a special memory card.

How does a laser rangefinder work?

Initially, high-precision distance measuring devices were developed for the military industry. Over time, these compact devices migrated to the civilian sphere. The operating principle of a laser rangefinder is based on the phase shift of the reflected laser beam. When the device is turned on, the built-in emitter generates a light beam of known wavelength and frequency. The beam reflected from the surface being measured is perceived by a photodetector.

The resulting phase readings of the reflected beam are compared with the original data in a special device - a microprocessor. After simple computational operations, the laser rangefinder provides an indicator of the measured distance. All these calculations are carried out in the shortest possible time in a fraction of a second. The error of household appliances is no more than 3 mm, while professional devices calculate the distance with an accuracy of 1 mm.

Which rangefinder is better – laser or ultrasonic?

When carrying out construction or repair work, it is important to quickly and accurately measure distances alone, without the help of other people. Using a standard tape measure is not always convenient, so specialized stores offer a huge variety of electronic measuring instruments. The most popular of them is a digital laser rangefinder, the operating principle of which was discussed above.

The most popular of them is a digital laser rangefinder, the operating principle of which was discussed above.

Ultrasonic models are also available. They work the same way as laser ones, but instead of a light beam they send a sound wave. The built-in receiver detects the reflected sound, calculates the time elapsed from the starting point of measurement and produces the desired value. The differences between these devices are as follows:

Measurement range
. With ultrasound it rarely exceeds 30 m, while laser can be used up to 200 m.
Accuracy
. For ultrasonic models it can reach up to 0.5-1% of the measured length, which is not always acceptable. In unfavorable weather conditions (snow, rain), the error may increase.

What you need to know about measurement error

The accuracy shows how accurate the instrument's readings are. Compared to ultrasonic models (with an error of 3-6 mm), laser analogues demonstrate better performance. It is important to know the following facts about measurement error:

Accuracy (error) is indicated in two ways: +/- 0.5% or +/- 1 mm.
The average error of household devices does not exceed 5-6 mm.
Professional and semi-professional rangefinders have an error of 1-2 mm.
There are highly specialized models for which high accuracy is not needed. For example, the error of hunting models can reach 1 m.

There is a concept of a reference point. Most models determine the distance starting from the rear end of the rangefinder. This system is convenient if you work indoors and measure the distance, for example, from wall to wall.

Some tools have multiple reference points, which expands their application possibilities. For example, if the reference point is the front end, this simplifies measurements on the external surfaces of the structure. When working with a tripod, the reference point becomes the tripod attachment point.

Choosing a reference point simplifies work in hard-to-reach places Source ivd.ru

Dependence of technology on conditions

The rangefinder has two functional units: an emitter, which contains a laser diode, and a receiver. Due to the electromagnetic wave, a laser beam is generated. The wave itself is produced by the rangefinder, then it is reflected from the working plane, be it floors, walls, ceiling or another working side of the object. After this, it is returned to the receiver. Each wave has its own amplitude and length. The last indicator is initially known to the rangefinder calculator, so further calculations are made using the principle of adding all the wavelengths that have traveled to the object and back. After this, the given amount is divided in half. And if there is a “cut” wave, then its indicator is added.

Comparative characteristics of several laser rangefinder models.

The resulting figure is displayed on the device display. The measuring quantity, that is, meters or centimeters, is set according to personal requirements.

The rangefinder works well in closed spaces, since in this case the distances are small and there is no interference at all. As for nature, there are several factors that can create errors in work:

Sun. Often the color of lasers is red, so the brighter the surface, the less visible the end point

Why is this so important? Because the rangefinder must be able to process the signal, but it will be too weak, which can affect the accuracy of the readings. Therefore, in the dark, laser rangefinder readings are more accurate. Environmental pollution

The best option is if the work is carried out outside the city, since the air there is clearer. In conditions of gas or fog, again there is a risk of errors. Reliability of rangefinder mounting. Manual measurements are always accompanied by inaccuracies. Therefore, it is better to use a special tripod for measurements. By the way, many modern devices already have such an element as standard. Working surface. If the measured plane has a dark color or a rough structure, the beam will be absorbed. Therefore, for such purposes, a light surface is used, which, due to its smoothness and color, helps to increase the reflectivity.

Error codes

When problematic situations occur, error codes are displayed on the Mileseey X5 screen. With their help, you can understand what the problem is and take measures to eliminate it.

Error code	Description	Solution
204	Calculation error	Read the instructions and repeat the procedure.
208	Excess current	Please contact the seller for warranty information.
220	Battery is low	Replace the battery
252	Heat	Turn off the device and let it cool down. Laser rangefinder operating temperature 0 - 40°C
253	Low temperature	Warm up the device to operating temperature 0 - 40°C.
255	The received signal is too weak or the measurement time is too long	Use a reflective plate or other highly reflective surface.
256	The received signal is too strong	The target is too reflective, use a target plate or do not aim at an object with strong lighting.
261	Out of measuring range	Select a measuring distance within the permissible measuring range.
500	Hardware error	Turn the device on/off several times. If the error still appears, contact your dealer for warranty assistance.

Principle of operation

Laser measuring instruments use two principles in their work - pulse and phase.

The first rangefinder consists of two components - a laser and a detector. By measuring the time it takes the laser beam to travel along the path from the source to the reflecting object, you can calculate the exact distance between them. These devices are used to work over long distances. The operating technology is as follows: the laser generates a powerful pulse and turns off. This property allows it to be used covertly. This property is the decisive factor determining the use of this device by the military.

The second type, phase, works according to the following principle. The laser turns on for a while and directs the beam to a distant object, it (the beam) has a different simulated frequency and the distance to the object is calculated from the phase change. Phase measuring distances do not have instruments for measuring the reflected signal. These devices are effective at distances of up to 1 kilometer and therefore are used for domestic needs or as sighting devices for small arms.

Scheme of operation of a laser rangefinder

A laser rangefinder, used in everyday life and in construction, is essentially a mixture of a calculator and a tape measure. Meanwhile, such a device has a number of undeniable advantages:

This device provides the ability to measure linear dimensions (length, height, width), while the built-in calculator will automatically calculate the perimeter. In addition, the calculating device will help determine the volume of the room;
The rangefinder is equipped with the ability to store received data in internal memory. They can be used to carry out calculations;

The device allows you to measure distances at remote distances with someone’s help; by the way, measurements can be taken both in indoor and outdoor areas, in different weather conditions.