Provided by S.M. Wahid Mahmud, Daffodil International University, Department Of Electronics & Telecommunication, Faculty of Science & IT.

1. PresentationOn MEASUREMENTS & MEASUREMENT SYSTEMS

2. Prepared By Name: S.M. Wahid Mahmud Email: redheart.786.st@gmail.com

3. IntroductionMeasurements & Measurement Systems are todays most important and useful topics to learn, discuss & identify. Human race are growing towards the most desireable future what they want from their beginning of life. Today we can not do anything without measuring our normal daily necessary things. So to do perfect measuring we need to measure correctly and perfectly. For that we should know the measuring procedure and measuring systems.

4. Definition Measurements Measurement Systems

5. 1. Measurements-Weights and measures were also among the earliest tools invented by human. In early years societies needed rudimentary measures for many tasks like, constructing dwellings of an appropriate size and shape, fashioning clothing and bartering food or raw materials. The measurement system was commonly used in the United States and today it is the same as that brought by the colonists from England. These measures had their origins in a variety of cultures and aspects. The ancient method, "digit," "palm," "span" and "cubic" units of length slowly lost preference to the length units "inch", "foot" and "yard". Comparison between the quantities, whose magnitude is unknown and a predefined standard is known as measurements. Means measurements are compared with the ideal measuring quantities.

6. 2. Measurement Systems-Measurement is a kind of process in which we can convert or change the physical parameters or explain the properties of any matter around us by ideal unit, i.e. length, mass, velocity, acceleration and time with meaningful number. But it is important to know every ideal unit to explain the matter around us or which we would like to describe. So we can say that knowing the units of physical parameters around us is necessary. Like we can say second is the unit of time, meter is the unit of length and m/sec2 isthe unit of acceleration. When we need to express any of these physical parameters then we apply these ideal units.

7. Methods There are two methods we follow to measure any physical parameters. The are- Direct Method Indirect Method

8. Types of Instruments In the study of the measurements & measurement systems there are three types’ instruments have been made. They are all of different in working procedure and measuring quantities. So we have to bevery careful of choosing which one to use. There are three types of instruments- Mechanical Electrical Electronics

9. 1. Mechanical Instruments Instruments like mechanical type are very reliable in static and stable condition. Mechanical instruments are very responsive in slow and perfect measuring condition. But these instruments have disadvantages in dynamic and faster response of measuring. In that case this type of instruments fails to measure perfectly. They are also unable to measure a heavy dynamic quantity of measurement and it also creates much sound pollution. Due to the measurement system of mechanical type, noise produced by it and perfect value is not found. We can say if we try to measure a slow gas pressure of any gas which is in a stable condition will be easy to measure. But if we try measure our local AC supply it will be impossible to measure.

10. A n a l o g A m m e t e r 2. Electrical InstrumentsThe electrical instruments mainly work by their electrical methods of indicating the output which much more rapid, fast and smother than the mechanical instruments. But every electrical instrument has a mechanical inertia problem when they are used for measuring. In this reason all the electrical instruments depend on the mechanical instruments have disadvantages like- i. Limited time & frequency response ii. Inertia due to mechanical part.

11. 3. Electronic Instruments The last and the final upgrade of the instruments are the electronic instruments. Today we have the most important and perfect measurement instrument. Instrument which has much more working abilities with the perfect range of measuring is the electronic instrument. In these days we use very fast and reliable instruments for our communications and devices. We have too many field of science where we need to measure perfectly and correctly and without a perfect measurement our entire experiment or job will be destroyed. Bio technical is one of the latest electronic instrumental technologies which have made our work easier and faster. As an example we can say about CRT, means Cathode Ray Tube. Modern science developed such type of electronic instrument which has no mechanical part in it and the only inertia of CRT is electron. But more less than we can think. Digital display systems of this kind of electronic devices are more flexible and user friendly. The electronic instruments are more efficient and easy to use. D I g I t a l V o l t M e t e r There are some advantages of electronic instruments- i. They are made with semi-conductor devices ii. Advanced higher sensitivity iii. Faster response iv. Greater flexibility v. Lower weight vi. Lower power consumption vii. Higher degree of reliability.

12. The electrical and the electronic instruments can be divided into two other types. Depending on their built in method they can be divided into- i. Digital Instruments- Digital instruments like DVM with ADC & DAC are their main characteristics.ii. Analog Instruments- These types of instruments can only measure the analog signal, like analog volt meter. They are also called PMMC in type.

13. Tangent Galvanometer Permanent Magnet Moving Coil (PMMC) The instruments from the left side is called, Permanent Magnet Moving Coil in short PMMC. The other one from the right side is called a Tangent Galvanometer. A Tangent Galvanometer has the mechanical inertia same as like the PMMC but PMMC is more efficient then the Tangent Galvanometer. The PMMC and the Tangent Galvanometer is also called Absolute Instrument.

14. The instruments from left and right are both same in category. They are known as Secondary Instruments. These instruments needs to follow a default scaling method. Liquid Glass Thermometer Basic Structure of A Glass Liquid Thermometer

15. All measuring instruments have various types of functions and applications. Functions- 1. Indicating Function- Vehicles have Speed Meter. 2. Recording Function- Digital Diabetics Checker.3. Controlling Function- Air Pressure Controller.Application-1. Monitoring- Digital Processing Analysis.2. Control of Process & Operation- Room Temperature Controller.3. Experimental Engineering Analysis- Formula Analysis.

16. Necessity of Measurements & Measurement SystemsThe importance and necessity of the measurements and measurement systems in our daily life is undeniable. If we look at our home and in daily maintenance procedure, we will find that in every step of our life we use the measurements and measurement systems. The small one but the very important one we can introduce is the voltage regulator. Modern version of the voltage regulator is UPS and IPS. We have home security system for monitoring which are a third generation measurements and measurement systems for controlling the security of our home. Alarm watch, stop watch etc is our good friends form the measurement systems group.

17. ConclusionNothing changes if we do not change them or wish to change. So it is our duty to do the right change in our system of science and technology with the perfect decision and measure. Here we have learned how we can find out the perfect measurement systems for our work; Working procedure and classifications of the measurements & measurement systems. But this is not the ending to our developing process to the measurements & measurement systems, because we want the best for our life.