Laser measuring devices (LMDs) use a projected laser beam to measure distances, allowing you to get accurate, single-handed measurements very quickly. I ‘ve been using one for several years to measure room sizes, cabinet runs, and ceiling heights in my remodeling business. Unfortunately, because my current LMD (Bosch DLR 130) is about the size and weight of two decks of cards, it’s never earned a permanent spot in my tool belt.
Recently, I was given the chance to try the Bosch GLM 15. Because the GLM 15 is less than half the size and weight of my old LMD and easily fits in my tool belt, I thought it might be more useful for day-to-day measuring tasks.
In fact, measuring 1 3/8 in. wide by 7/8 in. deep by 3 7/8 in. long and weighing just under 3 oz., (including its two AAA batteries) the tool’s most-notable feature is its size. The manufacturer gives its range from 6 in. to 50 ft. with accuracy to within 1/8 in. of the actual dimension. Units are expressed either as feet and inches to the nearest 1/16 in. or meters to three decimal places. All measurements are from the base of the unit to the object the laser dot is projected on.
The tool only has one button. A single press turns the device on and you’ll see the laser dot on your target. If you move the device or the laser dot, the display will show a continuously updated measurement. This feature is useful for stepping off dimensions or for finding the center of a long wall, for example. Pressing the button a second time holds the current measurement, so you can record it or make a mark. The 7/8 in., square LCD display shows the current measurement and the previous measurement.
To check the accuracy and repeatability of the GLM 15 I did some sample measurements, comparing it to my 25-ft. Stanley tape, Lufkin folding ruler, and my older Bosch measuring device. The measurements were within 1/16 in. consistently. I did find greater variation when I measured a countertop with a tile backsplash. In this test, the variation between the GLM 15 and the other measuring tools increased to 1/4 in., because of the reflective quality of the glazed tile. The instructions warn about measuring to transparent, reflective, porous, or rough surfaces, so I now put a piece of blue painters tape on difficult surfaces before measuring to achieve more-accurate readings. You can also use a piece of tape that overhangs the corner to measure to outside corners of a wall.
One complaint I have is with the display. You need a good light source to read the non-backlit screen and fractions are displayed on the far right of the screen in the shadow of the case. You can tip the tool to shine light on the right side of the display, but making the display a little larger or shifting the numerals slightly would be better.
One additional use I’ve found for the tool is as a quick-and-dirty laser level. By setting the unit on its side on my 9 in. torpedo level, the laser beam provides an accurate level line out to about 30 ft. before the beam broadens to 1/4 in. I’ve compared it to my CST/Berger iLM laser level and my improvised setup is accurate to within 1/8 in. at 30 ft. With the torpedo level and laser measurer I can quickly check floor and ceiling out-of-level conditions without getting out my laser level.
The GLM 15 sells for $50, making it a reasonably-priced and very handy tool. It won’t replace full-function laser measuring tools with advanced features like indirect measuring, angle measuring, and bluetooth connectivity, but its compact size and low price make it a good fit for my tool pouch.
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Smaller than a deck of cards, the Bosch GLM15 laser measuring device sells for $50 and has a range of 6 in. to 50 ft. The author's testing revealed it's accurate to 1/8 in. at 50 ft.
