Measurement in Safety in Physical Science Scientific Units of Measurement

Hundreds of years ago scientists from different countries used different methods of measurement and therefore could not communicate. England used 3 grains of barley to measure every inch, while the U.S. used a body part – a foot.

This was not accurate!! They developed a global measurement system known as International System of Units. It is known as SI instead of IS because the official name comes from a French system – Systeme International.

All SI units are based on the # 10 which makes conversion from one unit to the next very easy. We use SI to measure length, volume, mass, and temperature. Length - the distance from one point to another.

Prefixes: Kilo = 1000 Mili = 1/1000 Centi = 1/100 Deci = 1/10   The prefix used depends on the size of object being measures. Ex: measuring a long distance use kilometers You measure length with a meter stick.