Mar 09, 2016 introduction to mechanical measurement 1. A wide variety of mechanical measuring instrument options are available to you, such as usage, power. The magnitude of one of the quantity is unknown, and it is compared with the predefined value. Least count for steel ruler for example in a steel ruler, there are twenty divisions between each 10millimetre scale reading. Measurement instrument question paper for diploma mechanical. Join online course of mechanical instruments step by step. Without these instruments, it is not possible to measure the dimensions of the specimen. Instrumentation and measurement in electrical engineering.
Download ebook measurement instrument question paper for diploma mechanical measurement instrument question paper for diploma mechanical electrical measuring instruments objective types questions and answer electrical measuring instruments objective types questions and answer. Methods of measurement based on agreed units and standards. Find the current range of the instrument when used as an ammeter with the coil connected across a. A general template for a measurement system is illustrated in figure 1. The precision of an instrument indicates its ability to reproduce a certain reading with a given accuracy. Least count of the vernier calliper is the difference between the values of main scale division and one vernier scale division. Classification of measuring instruments electrical. In the field of magnetic measurements the mechanical equipment is mainly used for the positioning and moving of the sensor coil, hall probe etc. The two arms can be set along the faces between which the angle is to be measured. The protractor dial is marked in degrees with every tenth degree numbered. Theory and design for mechanical measurements, fifth edition. A protractor dial is mounted on the circular section of the base. However, an instrument which does not possess linearity can still be highly accurate. The selection of an appropriate measuring instrument for a particular application also depends on four factors, they are.
Measuring instruments plays a vital role in the engineering workshop. The size and type of parts to be measured, the environment temperature, humidity, dust, pressure, and so on, the skills required by operator, and. Generally instruments are classified in to two categories. This incremental change in input is referred as resolution. Vernier caliper is used to measure the dimensions of the given specimen like diameter outer dia and inner dia, length and depth, etc very accurately thats the reason it is also called as precision measuring instrument. The detailed explanation of vernier caliper is as follows. The measuring quantity can be voltage, current, power and energy etc.
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. Chapter 1 mechanical measurement presentation prepared by prof. These instruments are most widely used in engineering practice because they are simple and inexpensive. Basically such a system consists of part or all of four general stages.
Apr 02, 2017 bevel protractor is an angular measuring instrument capable of measuring angles to within 5 min. In this contribution the importance of mechanical tolerances is demonstrated with some examples and the principal rules in order to reduce the influence of mechanical errors are discussed. As they use mechanical parts these instruments cannot faithfully follow the rapid changes which are involved in dynamic instruments. Mechanical engineering measuring instruments answers. In electrical measuring instruments electrical energy is converted to. Measuring instruments, least count, parts name and details. Types and use of precision measuring instruments bright hub. Vernier caliper is a widely used linear measurement instrument with a least count of 0. Mechanical instruments are very reliable for static and stable conditions. Here is some most commonly used mechanical instruments for measurement in industries. A measuring instrument is a device for measuring a physical quantity. More concentration should on class room work and text book methodology. A manometer is an instrument that uses a column of liquid to measure pressure, although the term is often used nowadays to mean any pressure measuring instrument. General characteristics and selection of measuring instruments.
Pressure is an expression of the force required to stop a fluid from expanding, and is usually. A measuring instrument can directly show the measured value or it can show the equivalent value to known measure value of the same quantity. The instruments duty is to measure the given specimen according to the given dimensions. Ammeter, voltmeter, ohmmeter, and wattmeter are the example of the electrical measuring instrument. Important measuring instruments multiple choice questions. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. Mechanical and other engineering measuring tools and instruments. The methods of measuring mechanical quantities are discussed subsequently, overing both the basic and derived quantities. Mechanical design of a precision instrument for measuring the. Although there are a few good books available on metrology, the coverage of topics on mechanical measurements is either scanty or. About 19% of these are testing equipment, 4% are gauges, and 1% are laser rangefinders. I universal bevel protractor 1 it is an angular measuring instrument capable of measuring angles to within 5 min 2 the name universal refers to the capacity of the instrument to be adaptable to a great variety of work con gurations and angular interrelations. Mar 10, 2018 measuring instruments, least count, parts name and details in this video i explained about some basic measuring instrument with their parts name and least count. Electronics and electrical measuring instruments and their.
Precision refers to the repeatability of measuring process i. Our offered mechanical measuring instruments feature a set of various tools which are widely used for measuring purpose and feature perfection and an unmatched accuracy. Degree to which a measuring instrument gives repeated measurement of the same standard. It is basic instrument of measurement, consist of two types of scale. An instrument is a device in which we can determine the magnitude or value of the quantity to be measured. It consists of obtaining a quantitative comparison between a predefined standard and a measurand or unknown magnitude. To the user of measuring instruments a knowledge of their construction and accuracy is. It is used to measure linear dimensions like length, diameter, depth. Moritz gsi, darmstadt, germany abstract mechanical equipment is an integral part of each magnetic measurement. Types and use of precision measuring instruments bright. Here are 30 measuring instruments for mechanical engineer. Manufacturer of mechanical measuring instruments vernier caliper, vernier depth gauge, bevel angle protractor and thread pitch gauge offered by neno technical services, noida, uttar pradesh. Engineering metrology and measurements is a core subject for mechanical, production, and allied disciplines in all the major universities in india. They can be a single steel plate or a flexible tape type tool.
Calipers, micrometers, scales, measuring tapes, lasers, etc. The body of the instrument is extended to form one of the arms. Vernier method principle in this method, a vernier is used. Pdf this paper presents a new instrument for measuring roundness profiles of axially symmetric micro shafts with diameters below 250 micrometers. Mechanical measurements and instrumentation contents general concepts static and dynamic characteristics of instruments errors in measurements metrology sensors and transducers signal conditioning and data transmission display devices and recorders pressure and flow measurements temperature measurements displacement, velocity. The protractor dial is graduated in degrees with every tenth degree numbered. The protractor is the simplest instrument for measuring angles between two faces. Classification of measuring instruments electrical measurements. Classification of measuring instruments circuit globe. To do the perfect performance, an instrument should have some quality, here in this article we will discuss that. Mechanical design of a precision instrument for measuring. Instrumentation and measurement in electrical engineering xii chapter 6 gives an overview of instrument transformers, their uses, and testing methods for determination of phase and currentvoltage errors. In the physical sciences, quality assurance, and engineering, measurement is the activity of obtaining and comparing physical quantities of realworld objects and events. Vernier calliper is one of the most used mechanical measuring tools onboard ship.
Definitions and terms applicable to mechanical measurements. 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. Graduates in electrical or mechanical engineering or any of the physical sciences are taught the essential disciplines of measurement science to enable them to design electronic measuring. Calipers are nothing but the jaws which are used to fix the given component. Linear measuring instruments are used for the measure the straight surfaces of substances. Mechanical, electrical and electronics instruments. It is an independent domain of knowledge dealing with the measurement of various physical quantities such as pressure, temperature, force, and flow. These are designed by our professionals using the highest grade of material to enable strength and high durability. Different types of measuring tools and gauges used on ships.
At the end of this article you will find your pdf downloadable link. Mechanical measurement mechanical engineering test questions 1 the reliability of an instrument mean a the life of the instrument b the degree of repeatability within specified limits c the time interval between two responses of the instrument d none of these view answer hide answer. Measuring instruments, least count, parts name and details in this video i explained about some basic measuring instrument with their parts name and least count. The term measurement means the comparison between the two quantities of the same unit. About the book engineering metrology and measurements is a core subject for mechanical, production, and. Resolution of measuring instruments if the instrument is being used for measurement, there is a minimum change in the input for which certain detectable change in the output is observed. I probes may be mechanical, optical, laser, or white light, among others.
The science of mechanical measurements has its roots in physics. Units of measurement and their standards, which is concerned with the establishment, reproduction, conservation and transfer of units of measurement and their standards. Sep 09, 2018 the vernier caliper is a precision measuring instrument which is used to measure length, depth, diameter of the given specimen. The least count of a measuring instrument is the smallest change in. Digital multimeter is an example for the digital instrument. Rockwell hardness tester for measuring how hard a material is. These instruments gives the magnitude of quantity under measurement in terms of physical constants of the instrument e. May 09, 2017 however, an instrument which does not possess linearity can still be highly accurate. Double prismatic guide of 30 020 011 0 150 014 40 0. A basic view of all the electrical measuring instruments like ammeter,voltmeter,etc. This tool is one of the most famous measuring instruments in mechanical engineering. A measuring devices which use to measure or compare unknown quantity with standard quantity is called as measuring instrument in simple words, sometimes, the measuring instrument called as meter.
Some of the recent developments such as laserdoppler techniques, holography, have also been included. Types of precision measuring instruments used in industry. Bevel protractor consists of a base to which a vernier scale is fixed. It consists of two arms and an engraved circular scale. The ratio of measuring instrument output to the input dimension. Variable measuring instruments in hindibasicadvance mechanical measuring instrument. Measuring tools and gauges 528 3 side view much larger scale. Classification of measuring instruments instrumentation. Mechanical measurement mechanical engineering test questions. Ammeter, voltmeter, ohmmeter, and wattmeter are the example of. Chapter 7 describes the use of operation amplifiers in measurement technology, and how to use them. Different types of mechanical measuring tools and gauges used.
Least count value of one main scale division value of one vernier scale division. Classification of measuring instruments instrumentation and. Introduction to mechanical measurement linkedin slideshare. Bevel protractor is an angular measuring instrument capable of measuring angles with a least count of 5. Unit 5 linear measuring devices and linear measuring. In metrology the least count of an instrument is the smallest change in the value that can be measured with the measuring instrument. 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. Buoyant effect of the wind causes errors on precise measurement of. Classification of measuring instruments the instrument used for measuring the physical and electrical quantities is known as the measuring instrument. Apr 14, 2020 a measuring devices which use to measure or compare unknown quantity with standard quantity is called as measuring instrument in simple words, sometimes, the measuring instrument called as meter. Taper measuring instruments are used for the measuring slope type of surfaces on the components. Methods and techniques of measurements are becoming increasingly important in engineering in recent years laboratory programmes have been modernized, sophisticated electronic instrumentation has been incorporated into the programme and newer techniques have been developed. For measuring any quantity there must be some unit to measure and express. Oct 08, 2019 here are 30 measuring instruments for mechanical engineer.
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