Instrumments 01 Dimensioning Instrument Level Reviews, Measuring & Squares

Instrumments 01 Dimensioning Instrument Review

Once in a while, there are opportunities to review a tool and I immediately think (sometimes out loud for the whole office to hear), “I really want that!” That was the case when I first saw the email about the Instrumments 01 Dimensioning Instrument. The basic idea is that a rolling wheel, similar to a miniature trundle wheel, can digitally measure objects that have a curvature in the same way its big brother can measure the distance across uneven landscapes.


There are two writing versions in the form of a modern, sleek pen or pencil. A third option is available as just the tool in a much shorter form factor. With a laser as your guide, the tool offers extreme accuracy for non-standard shapes.

The dimensioning tool uses a small cell battery for power that claims to last up to 6 months. That all depends on your level of use, of course. Replacements are $20 for a two pack, so figure that into your cost of ownership since they aren’t rechargeable.

Instrumments 01 Dimensioning Instrument

Writing Quality

I have the pencil form and it uses fairly thick graphite – roughly the size that you find in the core of a #2 pencil. A three-pack of refills (6 per pack) will set you back $16.

As a writing utensil, it’s effective and fairly comfortable despite its simple tapered design. It has the look of a writing instrument that belongs in an architect’s office.

Instrumments 01 Dimensioning Instrument

The App


You’ll need an Android or iPhone to download the Instrumments App (sorry Windows Phone users). This is a requirement since there’s no way to use the tool without the app interface. The tool connects via Bluetooth and the setup process is pretty straightforward. I had a couple of connectivity issues during my evaluation period, but this isn’t the only device that happens with, so I’m chalking it up to my phone.

Like most apps, you can write a really long review just on using it, so I’ll spare you the majority of the details. The highlights for me are the ability to change between metric and imperial measurements, battery charge status, and saving multiple measurements for calculating area, volume, etc. Paying the monthly fee to unlock full access will most notably give you the ability to get your data into CAD drawings.

Instrumments 01 Dimensioning Instrument

The downside of being tied to an app is that you have to be able to see your phone screen to know what your measurements are. Since smartphones have a way of turning off their displays to save battery power, this can be a point of frustration if you have much time between measurements. In my use, it really means that this tool is at its best in the office measuring blueprints or perhaps in the shop. It’s just not as useful on the jobsite.

Accuracy and Precision


Precision and accuracy are often used interchangeably, but I’m going to be that annoying guy that brings back the scientifically correct uses. Accuracy refers to how close you are to a known value or measurement. In the case of measuring tools, it’s how close the 12″ mark is to exactly 12″.

When it comes to accuracy, the Instrumments 01 Dimensioning Instrument can get down to 0.1 mm. That’s quite a bit better than the 1/16” standard of accuracy we typically go for in the tool industry. I switched the measuring mode to inches and the precision level there is 0.01” – much smaller than the 0.0625” that is 1/16”. Against my most accurate tape measure, the Intrumments 01 can get close, but not perfect

Instrumments 01 Dimensioning Instrument



Precision is the ability to hit a mark consistently. In the case of a tape measure, precision usually isn’t a concern since the markings don’t move around on you. But digital measuring tools are a different story and it’s why they require calibration at some point. In the case of this tool, the app will guide you through a short calibration every time.

Precision is where the Instrumments 01 Dimensioning Instrument has a bit more trouble. I didn’t repeat a single set of measurements and get the same data set for any two. The closest I got was a couple of 4” measurements where I hit 0.01” from one to the other, but most were more than 0.1″ off.

Using the Training Wheels

While part of this might be the tool, it’s more likely an issue with the user (that would be me). Using the training wheels should help offer much better accuracy. Getting the training wheels on is a little tricky. You’ve got to push them forward into position with a little more force than you’d think is necessary. But you won’t break the adapter, so give the wheels a good shove into place.

Once in position, it does become easier to track than without the wheels. My accuracy improved some, but still not to the point that I could forgo a tape measure for most flat measurements.

As I eluded to, part of the inaccuracy is the tool itself. Simply setting the wheel down on a surface and picking it up again results in a small measurement. The wheel moves easily and my ability to set it straight down and pick straight up is more variable than an eye surgeon’s.

The tool and app track curves, so it takes a steady hand when you want to measure an object that’s straight and level. Additionally, getting a perfectly accurate start and stop point is challenging when you’re talking about the level of accuracy the 01 is capable of.

One possible solution is to go back to the wheel design and give it a tight pawl system like we see with SK’s X-Frame Ratcheting Wrenches so there’s a click for each movement. The tradeoff is that it is nearly impossible to keep the 0.1 mm precision if you do that. The alternative is to tighten the wheel up at the cost of some additional rolling resistance. Again, the training wheels should help in this department and to maintain the highest level of accuracy, you should always measure with them installed.


The Bottom Line

Instrumments 01 Dimensioning Instrument

The Instrumments 01 Dimensioning Instrument is built around a compelling concept for measuring objects that a tape measure just can’t do. The reality of its use isn’t consistent enough to back up its incredible precision claims. The ability to measure and track and shape of a curve means that any slight movement off your target line affects the outcome. And that’s a significant amount of error for someone like me that doesn’t have perfectly steady hands.

The learning curve involved in getting consistently good measurements along with the $149 price might be too much for most Pros. Adding on an additional $10 per month for full app functionality will probably relegate this tool to a small niche of users that can really take advantage of its capabilities. As a concept, it’s solid, but the execution still needs some refining for the majority of us to reap the full benefit.

Instrumments 01 Dimensioning Instrument Specifications

  • Model: Instrumments 01 Dimensioning Instrument + Pencil
  • Material: Aluminum and steel
  • Stated Accuracy: 0.1 mm (0.01″)
  • Price: $149 (additional $10 per month for full app functionality)

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