Diameter tape measures are made for wrapping around pipes and poles, to find the diameter. That’s a good enough reason to keep one in your tool box, garage, and vehicle. But there’s one feature that no one talks about, until now….
The other side of the diameter tape measure is a regular tape measure, in inches or centimeters. It measures length, not diameter. So, even though it is a special tape, it is also a handy every day tape, too. Lufkin, and the other manufacturers, thought of everything when they designed these handy pocket tapes. Everyone should have one or two.
There are distance measuring apps out there, but measuring the diameter of a pipe presents a unique measuring situation.
Calibration. There will need to be some way of checking to see if the app is working correctly. You will need to measure a known standard to see if the app is measuring right. If not, there needs to be some way of calibrating or adjusting the reading, to make it accurate. In other words, if you measure a 2 inch pipe, and the app says 2.1 inches, you need a way to adjust the setting to read 2.0 inches. Otherwise, when you measure a 3 inch pipe or any size pipe, the measurement would be off.
Calibration should be done with different sizes of pipe, to make sure you will get an accurate reading at any of those sizes.
The curvature of the pipe needs to be considered. You aren’t taking a picture of a 2D object. The pipe is 3D, so your camera may not see the top and bottom of the pipe as being 180 degrees away from each other. If you are too close to the pipe, you wouldn’t see the full 180 degrees. So your measurement would be too small.
Resolution of measuring. A pipe diameter tape measure normally has a resolution of 100th of an inch diameter. Can a smart phone app be that accurate?
The nearness of the object. For calibration, we would need some standard distance from the cell phone. Maybe this could be accomplished by using an object like a 12″ ruler, placed between the pipe and the phone. Hopefully, a less mechanical method will pop up.
If you know of an app that can accurately measure pipe diameter, please let me know. If one does not exist, I’m sure it will be invented in the near future.
This time, we won’t get into the geometry theory of pi that we had in high school. The magic of a pipe diameter tape measure is its simplicity of use. Here are the 3 steps to find the diameter of a pipeline:
Clean the pipe surface. Soil and any other contamination, of course, will make the pipe seem bigger than it really is.
Wrap the diameter tape around it, with the diameter scale visible to you.
Simply read off the tape. This will be the diameter, even though the tape is wrapped around the circumference. That’s all!
Some things to watch for…..Some OD tapes (diameter tapes) are marked in 100ths of an inch. Some are marked in 64ths of an inch. On the 64ths of an inch tape, 32/64 would be 1/2″. 16/64 would be 1/4″. 24/64 would be 3/8″. For convenience, you can use a magic marker to mark some of these common, but confusing measurements.
A diameter tape measure can save you a lot of time and frustration when you want to find the OD (outside diameter) of a pipe, post, or tree. This special tape has the inch scale (or metric scale) stretched out by a factor of pi (3.14159). So, if you wrap it around the pipeline, you will not see the “circumference”. You will see its diameter. You don’t need to divide your answer by 3.14159.
After you get one, and learn how to use it, you will use one every week for the rest of your life.
You won’t believe how you ever got along without one.
To help you on this fun journey as a FDTU, let’s find out…
What is a diameter tape.
It is a measuring tape that, when you wrap it around the circumference of a round object (pipeline or tree), it reads the “diameter”. If you would use a regular tape measure, you would have to divide by pi (3.14159) to get the diameter.
How to use a diameter tape.
You simply wrap it around a pipe or shaft, or tree, and have the diameter scale face outward, so you can read it. Make sure you don’t use the other side, because it would give you the circumference.
What you will use it on from now on, to make your life easier.
If you need to replace a car heater hose, but you want to have the new hose on-hand before you remove the old hose, use your diameter tape to measure the diameter (and length) of the old hose. You can do the same routine when replacing plumbing.
My friend owns a marina. He never heard of a diameter tape. I gave him a diameter tape and told him what it was for. He was in the FDTU group, and now he uses this valuable diameter tape measure every day.
Are you in the FDTU Group? Now you know how a simple tape can make your life easier.
Measure the diameter of a leaky heater hose on your car without taking it off and
letting it drip. Then get a new hose the correct size. Take off the old hose, and immediately install the new one.
When making changes to the copper pipe in your house, measure the outside diameter of the existing pipe, so you can buy the right size. Then you will have all the right sizes when you shut off your water, and start working. You won’t be interrupted by a hasty trip to the store.
Does your boat need a new hose, and you don’t want to remove the old one until you have the right size replacement beside you? Just measure the outside diameter (OD) of the old one, and match it to the new one.
A pipe diameter tape measure is quick and easy to use. If you ever need to do any repair work like this, you definitely need an OD tape (diameter tape).