SI system

(noun)

A series of units that is accepted and used throughout the scientific world.

Related Terms

Examples of SI system in the following topics:

  • Standard Units (SI Units)

    • The International System of Units (abbreviated SI) is the metric system used in science, industry, and medicine.
    • The International System of Units (abbreviated SI, from the French Système international d'unités) is the metric system used in science, industry, and medicine.
    • But in most of the world (including Europe) and in all scientific circles, the SI system is in common use.
    • The use of the SI system provides all scientists and engineers with a common language of measurement.
    • Causey teaches scientific units of the SI system, the metric system, and the CGS system.

  • SI Unit Prefixes

    • The basic SI units can be expressed as fractions and multiples of basic units by using a set of simple prefixes.
    • Now that we know about the SI system and what it provides to the scientist and engineer, we can examine some aspects of actual measurement.
    • The SI system utilizes a standard system of prefixes to the basic units that allow them to be more relevant to and descriptive of relative magnitude.
    • Briefly review the basic SI units before you study the prefixes.

  • Mass

    • Mass is a physical property of matter that depends on size and shape of matter, and is expressed as kilograms by the SI system.
    • The International System of Units (SI) measures mass in kilograms, or kg.
    • There are other units of mass, including the following (only the first two are accepted by the SI system):

  • Prefixes and Other Systems of Units

    • Today, the prefixes are standardized for use in the International System of Units (SI) by the International Bureau of Weights and Measures.There are twenty prefixes officially specified by SI .
    • The SI Unit system, or the metric system, is used by the majority of countries in the world, and is the standard system agreed upon by scientists and mathematicians.
    • This system of units was developed from the English, or Imperial, unit standards of the United Kingdom.The United States customary units define measurements using different standards than those used in SI Units.
    • The system for measuring length using the United States customary system is based on the inch, foot, yard, and mile.
    • Some units that are widely used are not a part of the International System of Units and are considered Non-SI Units.

  • SI Units of Pressure

    • The SI unit of pressure is the pascal (Pa), which is equal to one Newton per meter squared (N/m2).
    • The International System of Units (abbreviated SI from the French Système International d'Unités) is the basis of the metric system.
    • The SI was established in 1960 and is based on the metre-kilogram-second system rather than the centimetre-gram-second system.
    • The unit of pressure in the SI system is the pascal (Pa), defined as the force of one newton per square meter:
    • Since the quantities measured can have such a wide range, a standardized prefix system has been set in place.

  • Mass

    • The SI unit of mass is the kilogram (kg).
    • It is also the only SI unit that is directly defined by an artifact, rather than a fundamental physical property that can be reproduced in different laboratories.
    • Four of the seven base units in the SI system are defined relative to the kilogram, so the stability of this measurement is crucial for accurate and consistent measurements.
    • This value, though given in kilograms, is actually the non-SI unit of measure known as the kilogram-force.

  • Converting from One Unit to Another

    • Different systems of units are based on different choices of base units.
    • The most widely used system of units is the International System of Units, or SI.
    • There are seven SI base units, and all other SI units can be derived from these base units.
    • The seven base SI units are: [Physical Quantity: unit symbol (unit name)]
    • Derived units are based on units from the SI system of units.

  • Time

    • Time is the fundamental physical quantity of duration and is measured by the SI Unit known as the second.
    • Time is one of the seven fundamental physical quantities in the International System (SI) of Units.
    • Today, the SI Unit of the second is defined in terms of radiation emitted by cesium atoms.

  • Length

    • Length is a physical measurement of distance that is fundamentally measured in the SI unit of a meter.
    • The basic unit of length as identified by the International System of Units (SI) is the meter.

  • The Rule of Law

    • Government is a system for keeping the lid on problems posed by private-involuntary associations.
    • The classical formulation of this said that we should have "the rule of law. " A more specific way of putting it is: Laws, si; pseudo-laws, no!