A tape measure can solve basically one problem….How long is the item? But a pipe diameter tape measure can solve a short list of problems for you.

- What is the outside diameter (OD) of that pipeline, without having to cut into it. You don’t even have to divide by pi.
- What is the diameter of a tree trunk.
- What is the accurate diameter of a tire.
- What is the diameter of a beach ball, when fully inflated.

Even if the pipe is distorted, and the cross sectional diameter would be different in different directions, you can do it. The pipe diameter tape measure can tell you what the diameter would be, if it weren’t distorted. That’s because the measurement is based on the circumference. The tape automatically divides by pi (3.14159) for you.