Ryobi Professional Laser Distance Measure (RP4010)

The Ryobi Professional Laser Distance Measure (RP4010) is part of the new Tek4 family of cordless electronic tools. Don't think of an RP4010 as a supercharged electronic tape measure. While it considerably speeds up the job of taking length measurements, it also calculates area, volume, and minimum and maximum distances. As with all Tek4 tools, it's powered by a 4 Volt Tek4 battery. You can expect up to 2,000 measurements on a full charge.

At 1-1/2" x 2" x 4", the RP4010 is not much larger than a Blackberry. It stores in a fabric carry case that slips onto a belt. The 8 button keypad layout is simple and intuitive. The LCD screen measures 1-1/8" square,, which I found somewhat small. The screen is reasonably clear in daylight conditions; under dim lighting text on the screen is somewhat more difficult to read. I also find it difficult to read the fractions, even under the best lighting. Fortunately Ryobi has included a backlight, which really improves screen readability. I tend to switch it on all the time.

While the RP4010 is not a complicated device, I highly recommend you read the instruction sheet that accompanies the unit. Unfortunately, Ryobi has chosen to print the instructions on a huge 2' by 3' double sided sheet, which I found awkward to use. I ended up writing the salient instructions on a small 6" by 4" sheet of paper, which I folded to fit into the case.

The RP4010 displays measurements in feet and inches, inches only, feet only and meters, and you can switch between measurement units on the fly. Measurements are calculated, by default, from the back of the unit (so that you don't have to remember to add it's length onto each measurement that you take).

However, you can switch the measurement reference point to the front of the unit or to the end of the stop bracket, a small metal plate that unfolds from the underside of the unit. This enables you to take measurements from awkward or difficult to reach positions. With the stop bracket opened to the 90° position you can place the unit on the floor to measure the height of a ceiling. Each time you want to use the front or stop reference you have to manually select the option, which can be a nuisance when you want to take a number of readings from a non-default reference point.

By default, measurements are calculated from the back of the unit (B); you can change the reference point to the front (A) or the stop bracket

Stop bracket (closed position)

Taking measurements, whether for distance, area or volume is super quick. I can walk into a room of virtually any size and calculate the square footage in under 20 seconds. For a contractor, real estate agent, or home inspector, this represents a significant time savings. Ryobi claims an accuracy of 1/16" up to 195'. I've found that this is true - if you keep the unit rock steady. Moving it even slightly will result in a different reading; for me up to 1/8" off. It's best if you take several measurements from the same spot to see if you can hold the unit steady enough to get consistent results. Obviously, this won't be a problem if you don't require precise measurements.

However, if you do need highly accurate measurements (say, when measuring for cabinet installations) I suggest steadying the RP4010 against something immobile. A tripod mount on the bottom of the unit would have make it much easier for this purpose. I hold the unit flush against a wall when taking measurement, and I've tried stabilizing it atop a 4' length of 2 by 2 with good results. I took half a dozen measurements, and then compared them to measurements taken with a standard measuring tape. The results were virtually identical.

If you'll need to measure part of the height of a wall, or an opening in a wall, you can use one of two indirect measurement functions. The first (see Illustration 1) requires you to input two measurements - the diagonal measurement and the horizontal measurement - the RP4010 uses the Pythagorean method (a² + b² = c²) to calculate the vertical dimension. For the second indirect measurement function you input three measurements (see Illustration 2). Simple and very convenient. I've used the first indirect measurement function half a dozen times, and when compared to the measurement I get from a standard measuring tape, it's spot on.

Illustration 1

Illustration 2

Another interesting function on the RP4010 is the 'stake out' function. Say you want to mark out studs for a wall at 16" o.c. You input the stake out value (16"); as you move the laser along the wall the unit will signal each 16" increment. Way cool.

The RP4010 has a number of other intelligent features. If will let you know when it needs more time to take a reading, it turns the laser off after one minute of inactivity, and turns the unit off after three minutes of inactivity. I love this feature, as I usually don't remember to switch things off after using them. Another nice feature is the built-in timer with a 0 to 60 second delay function - gives you time to position the unit in awkward places before it automatically take the measurement.

There is a low battery indicator (very convenient), and a built-in bubble level (less useful, as it's really tiny - 5/16" x 5/8"). You can can scan a room and take minimum and maximum dimensions, and you can add and subtract measurements as many times as you want. And, there is a memory function that stores the last 10 measurements.

For hand held measurements keep the unit as steady as possible

Measurement taken with bracket support extended

As you can see, the RP4010 replaces the tape measure for a lot of measuring, especially for long distances, as well as significantly reducing the amount of time it takes to calculate square footage and volume measurements. Even using it for simple distance measurements easily justifies the purchase price. While the RP4010 could stand for some future improvement, the issues I have with it are fairly minor considering the increased productivity it offers.