Wndsn High-Viz Quadrant Telemeter

You can find the distance of something using a string and a plastic card, no batteries needed. Crazy, right? I’m told it’s actually ‘math’.

Note: this item was provided at no cost for review.

Wndsn XPD has been making these neat Quadrant Telemeters for a while now. To be honest, they are one of those items I have been aware of, but confused by. What are they for?

So when Wndsn asked if I would like to try one out, I jumped at the chance to get my hands on one. I, you see, am not someone trained in astrology, astronomy, navigation, or really math. So, as a pretty basic guy who is interested in cool stuff, this little card both baffles me and intrigues me.

It’s pretty neat, but hard to explain.

What Does It Do?

This is a quick calculator, which assumes you know a measurement of one thing to calculate other things. If you remember back to school, you likely learned these concepts in math class, but forgot how to actually calculate this stuff — this tool does this for you. With this, let’s say you know the rough height of something in the distance (like a door, or a person), you could then use this tool to calculate how far away that thing is — pretty quickly too.

Wndsn has a full page here which details the many uses, but here’s the part that makes the most sense:

The Quadrant Telemeter lets you measure angular size and compute distance, height or depth of object, altitude, or elevation, it allows computation of sine, cosine, and tangent for a given angle.

Like I said, the two most common uses most people will have for this is calculating the height of something, or the distance to something. And with the way this is setup, you can do so on any scale you want, so if you only know the height of something in feet, you’re going to be returned the distance similarly.

Simple, but complex. Overall very hard to explain.

My Usage

When you first get the Telemeter you are tasked with attaching the string and tying knots at specific points along the string. I personally struggled to do this until I got a pointy thing like the instructions show. I really think this would be better done before shipped out, but it is what it is. But this gave me the first taste of something I quickly accepted: this can be a precise tool, but I am not precise enough to use it for anything more than “good enough”. I suspect most people need to accept this as good enough, not precise.

The entire setup depends on you knowing something about the things around you. If you want to know how far away stuff is, you will need to know the height of one of the things you can see at that distance away. This can be easy if you see people, or doors. But tricky if you are in nature and all you see is trees.

That’s where the second part comes in, you presumably can always know how high your eyes are off the ground, and thus you can point the device to a spot out in the distance and calculate that distance just knowing those two things, crazy right? It is, this page explains how.

There’s a limit to that method, but there’s a limit to all the methods. This is not a laser distance tool — it’s not something that is going to get you super precision. In most cases it is going to get you good enough distances and heights.

I struggled to figure this tool out. And it wasn’t until I cheated that I could sort it out. By cheated I mean I knew the measurement of my front door, and I walked a known distance away from it. Then I used the Telemeter to calculate the height and distance, and kept playing until I got the correct (or close enough) results from the device. For me, that unlocked it and made the Telemeter far more useful over all.

It’s a really tricky device to learn, but easier once you get the hang of it. At least for height and distance, the other uses are beyond my current capabilities. Needless to say you keep the instructions with you on this one.

Most of my uses was playing with it to identify distances based on my height. This would be a pretty neat tool if I was hiking in areas where I don’t have cell phone reception and thus have no way of potentially knowing how much farther something is. But, for the most part given that tech solves this stuff easier, it is a great learning tool. Well and I guess there is always the EMP concern…


For the most part, I used this as a neat little thing to play with and see how good I am at eyeballing distances. But, generally, I don’t have a ton of uses for this in my day to day world. People who do spend time outside of cell phone coverage might find this to be a light weight and durable option for calculating distances. And educators can look at it as a modern day slide rule of sorts.

It’s pretty fun to play with, so why not get one?

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