Are you in the gas and oil business? Or any business that needs to keep continual records of data in the field. The best and safest way to make regular notations of gauge readings and pipe usage, is with a tally book. Oilfield tally books are small, weather-proof pocket sized notebooks that are protected by vinyl covers.
Diameter tape measures are able to give you the diameter of a pipe, pipeline, log, or any other round object. They do it in 1 easy step. All you do is wrap the pipe diameter measuring tape around the pipe and read off the diameter. A regular tape measure would give you the circumference. Then you would have to divide by pi (3.14159). That adds another step, plus you would need a calculator, pencil, and paper to arrive at the diameter.
Do you need to find the diameter of a pipe or pipeline, and you don’t want to have to divide by pi? Of course, you can do it that way–Measure the circumference and divide by pi. But a more accurate way is to use a pipe diameter tape measure.
Other ways: Use a micrometer that is big enough to do the job. Or use a caliper, then transfer the size to a rule, then divide by pi.
Diameter tapes make the job easy, by doing all the work for you on an oil, gas, or water pipe, or anything round, like a tree or telephone pole.