Units of measurement and their standards, which is concerned with the establishment, reproduction, conservation and transfer of units of measurement and their standards. An astonishing array of devices and tools allow humans to measure just about everything, including calculating travel distances, determining a boards length in construction, ascertaining air and water temperatures, analyzing wind speed, gauging the pressure inside a tire and measuring the distance around the globe. The tools are only available when viewing through adobe, not through the browser viewer. Characteristics of measuring instruments sciencedirect. Building construction measuring instruments procedures for determining accuracy in use part 10. Kyowas data loggers static strain measuring instruments and data analyzers enable highly stable and accurate measurement of a variety of phenomena detected by strain gages, straingage transducers and many other sensors including voltageoutput instruments and thermocouples. Use the measuring tools to measure distances and areas of objects in pdf documents.
These errors are due to the external condition of the measuring devices. Most practical instruments are designed to exhibit linearity because it maximizes the convenience of it use. Calculate area dimensions in cad drawings or measure distance between lines. One is to select instruments having at least a 10 to 1 ratio and the other is to select instruments having at least a 4 to 1 ratio. Calibration, in its most basic form, is the measuring of an instrument against a standard. Without these instruments, it is not possible to measure the dimensions of the specimen. Characteristics of instruments linkedin slideshare. Without them, parts could not be built accurately enough to be interchangeable. The classification of measuring instruments according to their accuracy is to be effected by drawing up classes characterizing different levels of accuracy for instruments of the same category. These encoders are widely used in a variety of measuring instruments as the length measuring system that can generate highly reliable measurement data. As the ear is capable of hearing sounds between 20 hz and.
Linear measuring instruments free download as powerpoint presentation. Chapter ii general characteristics of measurement systems. These instruments converts the energy of the measured quantity directly into energy that actuates the instrument and the value of the unknown quantity is measured or displayed or recorded directly. Angle measuring instruments i sine bar 1 a sine bar is made up of a hardened steel beam having a at upper surface. Ii instrumentation and measurements halit eren and chun che fung encyclopedia of life support systems eolss 12 1 1 1 ys xs s s 7 where s is the laplace operator. Measuring instruments, llc measuring and examining. These instruments are most widely used in engineering practice because they are simple and inexpensive. Static characteristics the static characteristics of an instrument are required to be considered for the instruments which measure unvarying process conditions. People in ancient times used the different parts of their bodies to size. Pdf instruments measuring the diseasespecific quality. Classification of measuring instruments electrical. Basis of measuring equipment suitability in quality control. The static characteristics are defined for the instruments which measure quantities which do not vary with time.
Unesco eolss sample chapters electrical engineering vol. Scope this recommendation applies to length measuring instruments hereinafter called instruments. Precision measuring and gaging od1642 lesson 1task 1 between two mating parts when certain allowances are designed in them. Good measuring instruments were a key to high volume production. The aim of the investigation is thus to determine based on the suitability values c g and c gk whether a measuring system using a standard.
Measuring instruments lecture measuring instrument. Classification of measuring instruments circuit globe. Click on the hyperlink of a speciic instrument in appendix ds table of contents to retrieve the informa tion about the instrument, determine whether it meets your needs, and ind out how to obtain a copy. Classification of measuring instruments the instrument used for measuring the physical and electrical quantities is known as the measuring instrument. To use the measuring tools you need the adobe pdf reader 8 or. Measuring instruments plays a vital role in the engineering workshop. Discover the different types of measuring tools youll need for measuring distances, dimensions, angles, planes, water pressure, temperature, time, speed, miles, ingredients, and blood sugar level. The magnitude of one of the quantity is unknown, and it is compared with the predefined value. Measurement instruments for assessing the performance of. The measurement of this linear horizontal distance between two points on the earth surface is known as linear measurement. Measurement process must be in a state of statistical measurement process must be in a state of. The instruments duty is to measure the given specimen according to the given dimensions.
Measurements performed by the laboratory and by subcontractors that it uses shall be covered by this system. The instruments of the standard gage product line were created to satisfy the clients on their query of reliable and economic measuring equipment, standing. Introduction to mechanical measurement linkedin slideshare. When you use a measuring tool, the measurement info panel shows. One can fit a straight line through the output values obtained from such instruments that exhibit linearity. Tolerancetoreadability ratio determines the selection of a measuring device for a specific application. It is necessary to apply flat mirror and flat mirror interferometer, because it is not possible to avoid movements in different directions. Using a least square minimization scheme is the most accepted method to fit a straight line.
The measurement type can be divided as, direct measurement method, optical. Others are also important, but they contribute in some degree to the qualities of validity. Such types of errors mainly occur due to the effect of temperature, pressure, humidity, dust, vibration or because of the magnetic or electrostatic field. We call the span of a measurement system the total length of the range. Nafees ahmed, asstt, prof, ee deptt, dit, dehradun. Instruments measuring the diseasespecific quality of life of family carers of people with neurodegenerative diseases. There are two rules with respect to tolerancetoreadability ratio. Measurements are always made using an instrument of some kind. Classification, absolute and secondary instruments, indicating instruments, control, balancing and damping, constructional details, characteristics, errors in measurement, ammeters, voltmeters. Use the following pieces of equipment to measure objects. Design, manufacturing and testing of gauges of all kinds. The term measurement means the comparison between the two quantities of the same unit. Difference between nonglass reflectors and electronic distancemeasuring prisms traditional glass prisms for distances up to 150 m 95. Buoyant effect of the wind causes errors on precise measurement of.
Calibration of measuring instruments on a coordinate measuring machine 129 figure 2. Classification, absolute and secondary instruments, indicating instruments. Evaluation in education qualities of a measuring instrument. With a need to make quality products which meet design specified tolerances, a large number of firms, research and development centers, and school and college laboratories use measuring instruments that have high accuracy and precision.
Floattype petrol tank level indicator page 3 instrument types active instruments2 the change in petrol level moves a potentiometer arm, and the output signal consists of a proportion of the external voltage source applied across the two ends of the potentiometer. Add and subtract decimals and determine the tolerance range of given dimensions. Liquid measuring instruments 662 00 includes shipping and handling 5. Types of precision measuring instruments used in industry. Measuring instruments, llc 5873 centre avenue pittsburgh, pa 15206 usa. Qualities of a measuring instrument among the qualities of a test, whatever its nature, four are essential, namely, validity, reliability, objectivity and practicability. Measuring with an outside micrometer 01 inch using ball gauges with a micrometer. Rulers, stopwatches, weighing scales, and thermometers are all measuring instruments.
Then double click the last point, or hold the pointer over the last point and click. Precision measuring instruments wiki odesie by tech. Linear measurement can be achieved by various instruments. Measuring instruments the device used for comparing the unknown quantity with the unit of measurement or standard quantity is called a measuring instrument. The selection of measuring instruments is a complex task, which depend on the size, the character and the value of measured magnitude. Try to step back in time and imagine a world without measurement tools. Download 10 measuring instruments and their uses pdf at the end of the article. Types and use of precision measuring instruments bright.
Generalized performance characteristics of instruments. For instance, the most popular norm on management systems, i. All the static performance characteristics are obtained by one form or another of a process called calibration. The static characteristics of an instrument are, in general, considered for instruments which are used to measure an unvarying process condition. Your pc may be set up so that images open in the browser. Measurement errors environmental errors due to conditions external to the measuring instrument, including conditions in the area surrounding the instrument, such as effects of change in temperature, humidity, barometric pressure, or magnetic or electrostatic fields.
In zeroorder instruments, there is no frequency dependence between the input and the. Linear measurement in engineering survey, the linear horizontal distance is to be measured to complete a survey. This video covers the topic introduction to circuit parameters and energy sources dependent independent of unit i, electrical technology playlist. Introduction the adjustment of the periodicity of calibration of measuring instruments is a topic extensively discussed in the specialized literature and in major measurementrelated technical events. As instruments become more complicated, successfully identifying and applying best practices can reduce business expenses and improve organizational capabilities.
Linear measurement types, instruments and common errors. Measured value vs true valuemeasured value vs true value truetruevaluevalue unknown and unknowable reference value. Methods of measurement based on agreed units and standards. Finally, note the class or classes of measurement instruments most relevant to measuring the indicators of interest column 3. Idrac centre dessais en vol, france volume iv, part hai chapter contents page iia1. The purpose of this paper is to analyze the existing methods.
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