Metric measurements — also known as the International System of Units, or SI — are managed by a formal international organization. The rulers of the rulers have rules, and "hellabyte" and ...

Dosimeters used to measure radiation at laboratories, hospitals and in the field must be calibrated against a national standard to ensure that measurement results are consistent with the International ...

A nanometer (nm) is a unit of length in the metric system, defined as one billionth (10-9) of a meter (m). The meter is the base unit of length in the International System of Units (SI), making the ...

A nanosecond (ns) is a unit of time in the metric system, equal to one billionth (10-9) of a second (s). The second is the base unit of time in the International System of Units (SI), making the ...