A differential transformer is one of the most useful variable inductance transducers, it provides on alternating current voltage output proportional to the displacement of. Disadvantages of mechanical comparators they have more moving linkages, due to which friction is more and accuracy is low. Small displacements of a measuring plunger are initially amplified by a lever mechanism pivoted about a point as shown in figure. Where can i download pdf of engineering metrology by ic gupta. Mass comparators from mettlertoledo ensure full traceability down to nanogram resolutions allowing determining even smallest difference is mass. Modern metrology has its roots in the french revolutions political motivation to standardise units in france, when a length standard taken from a natural source was proposed. Comparators play a vital role in making electrical and electronic projects. Unit 6 angular measuring devices devices structure 6. Sigma comparator is a most popular, britishdesigned, british manufactured mechanical comparator. Jan 05, 2018 the comparator is an indirect type of precision measurement because it will not measure the dimension, it will indicate the difference in measurement between the given component and working standard, and another magnification instrument is needed to measure this difference with accuracy. Mechanical measurements and metrology books free download.
Hence it can be used to measure diameters length, squareness, parallelism, concentricity, taper, centre distance between holes etc. The various ways in which the comparators can be used are as. It establishes a common understanding of units, crucial in linking human activities. Generally, a diaphram is made of rubber type material polymer, in sigma comparator there are 2 number of slit diaphram is provided to have frictionless linear movement of the plunger. Metrology may be divided depending upon the quantity under consideration into. Engineering metrology and measurements is a core subject for mechanical, production, and allied disciplines in all the major universities in india. There are different types of comparators are available. Metrology is a significant department of mechanical engineering that deals with the measurement of a workpiece. Engineering metrology and measurements is a textbook designed for students of mechanical, production and allied disciplines to facilitate learning of various shopfloor measurement techniques and also understand the basics of. Pneumatic comparators lecture 3 measurements and metrology 2nd year industrial. The range of the instrument is limited, because the pointer moves over a fixed scale. Windowrange mass comparators are used for mass calibration and mass determination. Find here online price details of companies selling mechanical comparator.
The air is supplied at 5 bar to the control jet, which has a diameter of 0. A differential transformer is one of the most useful variable inductance transducers, it provides on alternating current voltage output proportional to the displacement of a core passing through the windings. The comparator plays an important role in the electronic circuit design. Offering capacity up to 5000 kg and readabilty up to 0. Krishnamurthy engineering metrology and measurements is a textbook designed for students of mechanical, production and allied disciplines to facilitate learning of various shopfloor measurement techniques and also understand the basics of mechanical measurements. It is therefore necessary to ensure that the measuring loads are the same in comparative measurement. In mechanical comparators, magnification is achieved by various mechanical devices and mechanical linkages. A dial indicator or dial gauge is used as a mechanical comparator. The general principle of comparator is to indicate the differences in size between the standard and the work being measured by means of some pointer on a scale with sufficient magnification it thus does not measure the actual dimension but indicates how much it differs from the basic dimension. Comparators mechanical engineering mcq questions and answers. Metrology and measurements pdf notes mm pdf notes smartzworld. Metrology and quality control by vinod thombre patil. The accuracy of instruments is affected due to friction between moving parts. I am glad to present the vth edition of book entitled metrology and quality control for iiird year diploma in mechanical engineering as per the g scheme code syllabus prescribed by msbte.
The magnification of plunger movement can be obtained mechanical means such as levers, gear and pinion. Mechanical comparators dial indicator reed type comparator sigma comparator johansson mikrokator 2. What are the different types of mechanical comparator. The term mechanical comparator is also called as microcator. Manual mass comparators and metrology from mettler toledo.
Mechanical measurement and metrology 2141901 department of mechanical engineering darshan institute of engineering and technology, rajkot 1 1 experiment 1 aim. Mechanical comparators are sensitive to vibrations due to high inertia. Introduction to metrology i metrology is the science of measurement i dimensional metrology is that branch of metrology which deals with measurement of dimensions of a part or workpiece lengths, angles, etc. Comparators and angular measurement chapter outline comparators introduction to comparators characteristics uses of comparators classification of comparators. List out any four angular measuring instrument used in metrology. Pdf engineering metrology and measurements books collection.
Unit 6 angular measuring devices angular measuring. Mechanical comparator is a measuring instrument and the mechanism of this instrument is in the form of tape spring twisted, and that is positioned. Mechanical comparator article about mechanical comparator. Pneumatic comparators are the widely used precision instruments which use the principle of obstructed nozzle.
Mikrokator, sigma comparators, optical comparators. Mv video based metrology systems are easytouse, general purpose, noncontact measurement systems with zoom optics. Lvdt is the most popular electromechanical device used to convert the mechanical displacement into an electrical signal. Z height is measured by moving vertically to maintain focus. The second part of this guideline is of procedural nature and gives practical advice to calibration laboratories. Get info of suppliers, manufacturers, exporters, traders of mechanical comparator for buying in india. In sections 5 and 6 an example of a typical calibration procedure is presented. This is available in various choices of scale ranges.
Download engineering metrology and measurements by raghavendra. Metrology is oftentimes called the science of measurement that depends upon two significant factors. The factors are time and quantity, which has to be measured by an engineer in order to ensure the precision of a workpiece. Mechanical measurements and metrology mechanical measurements and metrology 10me42b unit 3 comparators and angular measurement instructor. Types of comparators are categorized into several kinds, namely electronic, electrical, optical, mechanical, sigma, pneumatic and digital comparators.
Sartorius offers a range of manual and electronic mass comparators and metrology equipment for mass determination and calibration of weights. As the name of the comparator itself suggests, this is a part mechanical and part optical comparator. Very high amplification of order into 30,000 is possible. Chapter 6 gives the conclusion and describes the future work that can be done. Ijsrd international journal for scientific research. Millimess mechanical dial comparator mahr metrology. Different types of comparators and its applications. Linear measurement comparators mechanical comparators dial. It is noted that laboratories working according to isoiec 17025 shall validate their calibration. The various ways in which the comparators can be used are. Mechanical comparators are the type of comparator which is made up of mechanical means. It is a knifeedge shaped metallic strip, which is fitted with the plunger. Lvdt is the most popular electro mechanical device used to convert the mechanical displacement into an electrical signal.
A highly stable mechanical design and precision linear bearings achieve superb performance. In mechanical comparators, the required magnification is obtained by using mechanical linkages, levers, gearing and other mechanical devices. Pdf mechanical measurements and metrology mechanical. The comparators are classified according to the principles used for obtaining magnification. In most instruments used in fine measurement, comparators, bench micrometers, etc. The comparator is an indirect type of precision measurement because it will not measure the dimension, it will indicate the difference in measurement between the given component and working standard, and another magnification instrument is needed to measure this difference with accuracy. Engineering metrology and measurements is a textbook designed for students of mechanical, production and allied disciplines to facilitate learning of various shopfloor measurement techniques and also understand the basics of mechanical measurements. Although there are a few good books available on metrology, the coverage of topics on mechanical measurements is either scanty or. Mechanical metrology and measurements iit notes ebook download rar please suggest book for sub. As an alternative solution for this a mechanical optical comparator can be developed for achieving the. Comparators mechanical engineering mcq questions and. Comparator introduction comparators are one form of linear.
To understand calibration of various measuring devices. Mass comparators and metrology calibration sartorius. A comparator is a precision instrument used to compare the dimensions of a given workpiece component with the actual working standard. The special end of the contact plunger rests against the outer end of the first movable mirror so that any. Mechanical comparators engineering tolerance scientific. I dimensional measurements at the required level of accuracy are the essential link between the designers intent and a delivered product. Metrology and quality control get best books pdf, study. Types of pneumatic comparator with diagrams metrology. Metrology may be divided depending upon the quantity. Millimess mechanical dial comparator, mm mahr metrology. X and y dimensions are measured by moving the stage horizontally. Chapter 5 provides the results and simulations of different comparators studied. Pdf engineering metrology and measurements by raghavendra.