Fundamental and Derived Units

By =1. M Noman Raza

Discipline = TS 1

Topic

Definition of Measurement

Dictionary = It is defined as the act of measuring or the size of something.For examples = measurement means the use of a ruler to determine the length of a piece of paper. Scientific = It is defined as rules for assigning numbers to objects in such a way as to represent quantities of attributes. It consists of rules for assigning symbols to objects so as to 1) represent quantities of attributes numerically (scaling) or 2) define whether the objects fall in the same or different categories with respect to a given attribute (classification)

The quantities which can be measured are known as physical quantities.For example = length , time and e.t.cNon physical quantities are love , hate and e.t.cIt consists of at least a magnitude and a unit For example = 5mThere are 2 type of physical quantity 1)Scalar2) Vector

PHYSICAL QUANTITIES

SI UnitsThe International System of Units, defines seven units of measure as a basic set from which all other SI units are derived.We define unit as 1.0 . For example 5m means 5 * 1.0 m i.e 5m length is 5 times the length of 1.0 m .SI stands for “system of international” units.It is written as SI not S.I units.

SI units

Base or Fundamental units

Supplementary Units

Derived Units

WHAT ARE FUNDAMENTAL UNITS

catch a train buy petrol have an x-ray eat safe foods travel by aeroplane use your mobile

Measurement is everywhere, playing a vital role in our lives. Metrology is the science of measurement and National Metrology Institutes around the world make sure that the measurements we use are fit for purpose. In the UK, the measurement infrastructure is provided by the National Measurement System (NMS).

How could you do the following everyday activities without measurement?

Measurement Matters

Why measurement is important ?Measurement underpins the welfare of a modern society and touches

almost every part of daily life:

• Ensuring the safety and effectiveness of healthcare diagnosticsand treatments

• Measuring the composition, energy value and quantity of gaspiped to our homes, or of fuel in our vehicles

• Ensuringsafe operation of aircraft in flight • Ensuringconsistency of international time standards so we can

communicate reliably and navigate accurately throughout theworld

• Quantifying emissions of greenhouse gases to understand andmitigateclimate change

• Ensuring the security and sustainability of our food supply • Ensuringfairness between buyers and sellers in marketswhere goods are sold by weight or volume

Measurement plays a fundamental part in the innovation process. To develop new products and processes, companies need to measure quantity, quality and performance. To trade successfully, companies utilise a regulatory framework, based upon measurement confidence, ensuring access to global markets that are fair and open and without unnecessary barriers to trade. Supporting this is an established infrastructure of traceable measurement linked seamlessly to the national standards maintained . In some industries the need for accurate measurement is critical. For example, companies manufacturing precision engineering components used in aero engines will be working to tight specifications and must be able to measure size, material composition and performance to very accurate levels. For many of us a visit to a hospital may not be desirable, but knowing that the treatment has been appropriately measured throughout its development, trials and final delivery to the patient, is vital to confidence in its application and effectiveness.Measurement provides structure, removes chaos, reduces waste, ensures open and fair markets, supports precision where required and saves lives, money and time.

Measurement plays a fundamental part in the innovation process. To develop new and improved products and processes, companies are looking for: • improvements in quality orperformance • reductions in waste • use of new materials ortechniques All of these require appropriate measurement support. For many organisations, their first interaction with measurement is through the route of compliance with a standard. NMS expertise forms an input to over 800 standards committees to ensure that the measurement requirements are appropriate and that there is an infrastructure in place to enable organisations to demonstrate compliances.

Measurement helps innovation

SI Base Units