Question

Why do scientists need a standard system of measurement?

Answer 1

"Without standard units of measurement, scientists would have a huge problem understanding what other scientists were saying. After all, if I were to refer to a meter as "the length of my leg" and another scientists were to refer to it as "the length of a Saint Bernard dog", we'd have a lot of trouble when it came to do actual science. To avoid this problem, the SI system of units gives us a convenient and, more importantly, standard set of units that we can agree on."

http://socratic.org/questions/why-are-standard-units-of-measurement-important-to-scientists

to break that down, scientists need a standard system of measurement because there needs to be consistency.