What Are Units of Measurements Used by Scientists?

International System of Units

• Seven basic units of measurement are defined by the International System of Units (SI). All other SI Units are derived from these base units. Meter is the SI Unit for length and is expressed as "m". The SI unit for mass is the kilogram, abbreviated as "kg". The second, shown as "s", is the standard unit for duration. "A" signifies ampere, which is the unit for electric current. The Kelvin, denoted as "K", is the SI base unit for temperature. Candela is the base unit for luminous intensity and abbreviated as "cd". Mole is the base unit for the amount of substance and is written as "mol".

Natural Units

• Physical units of measurement used in physics are called natural units, which are based upon universal physical constants. Natural units are called such because they originate from natural properties rather than human constructs. The intention of natural units is to simplify or normalize certain universal physical constants by setting them as a numerical unit of one. Systems of natural units include Planck units, Heaviside-Lorentz units, Gaussian units, Stoney Units and Atomic Units.

Unusual Units

• Studying natural events like the weather also involves units of measurement that are unique to particular phenomena. Beaufort scales are used to measure wind velocity. The brightness of a lunar eclipse is measured using the Danjon Scale. The Saffir-Simpson scale is used to measure the ferocity of hurricanes in US while tropical cyclones are categorized on a 1-5 scale in Australia. There are also units of measurement for volcanic explosivity, wind chill factor and earthquake strength. The medical field also has units specific to certain events, such as the Glasgow Coma Scale and APGAR scoring used for newborns.

Non-Standard Units

• There are many non-standardized units of measurement used in science. One example of a non-standard unit is a ton of TNT, with kilotons, megatons and gigatons used to describe the power of explosions, nuclear weapons and volcanic eruptions. The weight of the sun, or solar mass, is used in astronomy as a unit of measurement for stars and galaxies.