Bosch Professional GLM 50-27 C test: a complete and resistant laser rangefinder

The Bosch Professional GLM 50-27 C laser rangefinder adopts the brand’s usual aesthetic codes. Dressed in blue plastic, it is largely covered by a soft plastic which guarantees both resistance to falls and a good grip in the hand. The robustness and the quality of manufacture are at the rendezvous. This German model also displays an IP65 certification which ensures sealing against dust and water splashes. Enough to use it serenely in environments that are not very welcoming for electronics.

The quality of the finishes is of particular importance for a laser rangefinder. Indeed, the slightest deviation on one of the sides of the device can be the cause of a deviation of the beam and therefore of a measurement error. Here, the four faces that can be used during a measurement are perfectly flat.

The color screen is quite small at less than 1.8 inches diagonally. However, it is bright enough to use even in direct sunlight. It is possible to reduce the brightness in the menus to save energy and, above all, not to dazzle too much when working in the dark. Information is displayed clearly to be understood at a glance. One of the advantages of the Bosch Pro GLM 50-27 is to offer screen rotation so that the display follows the positions of the device. This may seem trivial, but turns out to be very practical in use. A “big numbers” mode allows to increase the font size of the measurement result.

The GLM 50-27 C is operated through seven buttons spaced well enough apart to be identified with gloves. The functions associated with each button are quite clear and the handling of the Bosch Pro rangefinder is carried out without any problem. Each press of a key is accompanied by a small beep, audible warning which also validates the performance of a measurement. This indication allows you not to have to keep your eyes riveted on the screen to know if the measurement has been made: practical when measuring a distance in an acrobatic way. The good idea of ​​the GLM 50-27 C is a vibration feedback which signals the success of a measurement. This allows you to be informed even in a noisy environment or if you want to deactivate the sound alerts.

Navigating the Bosch Pro Laser Rangefinder menus is smooth and intuitive. The Func button (for functions, or functions in good French) opens a selection wheel. Scrolling is triggered by the keys on either side. Even though the pictograms and the text that accompany them are rather explicit, it is possible to access a short illustrated tutorial for each type of measurement. Well thought out, again. Access to the various settings of the device is also very simple. Getting started is quick, despite a large number of possibilities.

The Bosch Professional GLM 50-27 C works by default with two AA/LR6 batteries. An interesting solution since they are easily found on the market if needed, and it is possible to opt for rechargeable batteries for a minimum of ecological virtue. The German offers an optional 1 Ah rechargeable USB-C battery. This solution is to be reserved for those who frequently use their rangefinder, because lithium batteries do not like deep discharge in the event of prolonged non-use.

A detachable wrist strap and a storage pouch that can be attached to the belt accompany the Bosch Professional GLM 50-27 C.

The Bosch Professional GLM 50-27 C laser rangefinder has a range of 50 m and minimum measurements of 5 cm, all with an accuracy announced at 1.5 mm. This model is designed for indoor use and therefore does not include a viewfinder. Like most laser rangefinders that have passed through our laboratory, the GLM 50-27 C does not show any noticeable drift in the accuracy of measurements at distances greater than 2 m. Not having a room offering 50 m in length, we were unable to evaluate the very long range measurements.

For short measurements in a niche of 37 x 37 x 38.5 cm, the German model tested here ranked among the best students. It did not exceed 1 mm deviation from the reference value. The worst rangefinders in this exercise show differences that reach 6 mm, which is much more disabling. Strong luminosity on the area where the laser is projected does not prevent the GLM 50-27 C from carrying out its measurement.

Like the majority of laser rangefinders currently on the market, the Bosch Pro is capable of measuring distances, areas and volumes. A function offering to add the results of several measurements or series of measurements is also included in the program. The GLM 50-27 C also offers continuous measurement. When the feature is active, the rangefinder has three options. The first consists of taking minimum and maximum readings over a period, the second gives a distance in real time with a maximum text size for perfect visibility, while the last brings up a display mimicking a tape measure. The frequency at which measurements are made in this mode is particularly high, without the rangefinder ever showing any slowdown.

It is also possible to set the Bosch Professional GLM 50-27 C to measure a regular interval. Once the distance between each element has been entered, all you have to do is move the rangefinder so that it indicates each interval with an audible signal.

It is not always possible to evaluate a length directly. To remedy this problem, the Bosch Pro GLM 50-27 C offers several indirect measurement functions. The first two make it possible to measure height and length thanks to the Pythagorean theorem. A measurement of the hypotenuse combined with the angle value communicated by the inclinometer delivers, for example, the height of a wall to which there is no direct access. The third function is based on the inclinometer and allows for example to measure the height of an element on a wall. For maximum accuracy, the use of a tripod is highly recommended.

Such an accessory is not always practical to carry and the Bosch Professional GLM 50-27 C is capable of certain precision even freehand. This is largely due to the speed at which measurements are made by the German rangefinder. The faster the recording of the measurement, the more we avoid measurement bias attributable to hand tremors when taking a measurement. It is still better to work with a support on a wall, the ground or a stable surface.

The inclinometer present in the GLM 50-27 C is able to assess the position of the device in all directions. This allows it to grant a very useful function: the level. Like a spirit level, simply lay the rangefinder flat to know the inclination of the support.

The Bluetooth connectivity of the Bosch Pro GLM 50-27 C allows it to link to a smartphone. On the latter, it is necessary to install the MesureOn app from the German manufacturer. Pairing is very simple, and once connected, the rangefinder sends all its measurements to the app. This notably allows it to overcome the limit of 30 measurements recorded internally.

The MesureOn application is very easy to use. On its home screen, folders are presented as tiles. It is possible to create different folders, called “projects”, which can group together several “workspaces”. These appear as a large blank page of graph paper.

On this page, MesureOn gives the possibility to add parts, photos or notes. For the first, all you have to do is roughly draw a shape on the touch screen of the smartphone for the app to transform the line into a rectangle. It is then possible to modify the angles of the room and to enter the lengths of the walls. To do this, the user is free to choose between drawing from the measurements already recorded by the app or taking new ones in real time.

The Bosch application does not offer a 3D view of the parts created. However, it is possible to switch to a display of the walls to insert doors and windows, always being able to take measurements in order to place these elements precisely. Too bad it is not allowed to create the map of an entire floor. It is necessary to be satisfied with a display piece by piece. The system leaves relatively little room for maneuver for parts with an atypical format.

MeasureOn lets you take a photo, then add length notes to it. Convenient for giving information on a specific point. Finally, text notes can be inserted into projects.

Exporting data from the app can only be done in PDF format. The user chooses between exporting data for a single part or an entire project. The presentation of said data is clear and concise with an overview where the total surfaces, volumes and perimeters are calculated. This is followed by the room(s) that we will have created beforehand, again with all the values ​​of lengths, surfaces and volumes, as well as a breakdown of the information wall by wall. Photos and text notes appear next.

Too bad you can’t extract the data from the application just to use it in CAD software.