Field calculations are valuable because they turn a rough situation into a more informed decision. Their value drops quickly when the tool is difficult to check, slow to use, or unclear about what its answer means.
Clarity is part of accuracy.
A trustworthy result starts with visible inputs, familiar units, and a calculation that is easy to follow. The person using the tool should be able to spot a mistaken value before it becomes a mistaken decision.
That is not a compromise on rigor. It is what lets rigor survive the conditions of real work: limited time, changing conditions, and equipment that needs attention now.
Keep the tool close to the task.
A field tool earns its place when it answers a useful question with minimal ceremony. It should help the technician move from measurements to a next step, while retaining enough context to explain or verify the result later.
The best tools respect the judgment of the person using them. They reduce repetitive effort and make uncertainty visible; they do not pretend to replace experience.