Measurements and instrumentation objective type questions. These types of instrument are generally used for the measurement of high voltages but in some cases they can be used in measuring the lower voltages and powers of a given circuit. I instrument the most common ammeter and voltmeter for laboratory or switch board use at power frequency are the moving iron instruments. Feb 15, 2012 moving iron instruments moving iron instruments are the most common instruments used for measurements of electrical quantities. In moving iron instruments, a plate or van of soft iron or of high permeability steel forms the moving element of the system. The resistance in the circuit of the moving coil of a dynamometer wattmeter. The current to be measured is passed through the coil, coil produced the magnetic field.
It is based on the principle of the bimetallic strip the sandwich of metals with different. If this meter is to have full deflection at 5a, what is the value of the shunt. Working principle of moving iron instruments electrical. Working principle of a pmmc instrument when a current caring conductor is placed in a magnetic field. Whenever a piece of iron is placed nearer to a magnet it would be attracted by the magnet.
Inside this coil there are two pieces of soft iron, one piece the fixed iron remains stationary, while the other the moving iron is fitted to a spindle and can swing away from the fixed iron. Transformer basicsworking principle,construction,types. They position the readwrite arm more quickly, precisely, and. The permanent magnet moving coil instrument or pmmc type instrument uses two permanent. In older hard drives, the actuators were stepper motors. In the attraction moving iron instrument a specially shaped piece of soft iron with a pointer attached is pivoted near to the open end of a short solenoid fig.
The vitros 5600 features a broad menu of assays that covers 90% of the menu needs and 99% of the testing volume of a typical lab. Jun 01, 2019 actuator that moves the readwrite arm. Basic electrical and electronics engineering notes pdf. The electromagnet is the temporary magnet whose magnetic field strength increases or decreases with the magnitude of the current passes through it. Moving iron instruments measuring instrument electromagnetic. Functional principle moving iron mechanism with mcore system, silicon oil damping and resilient jewel.
Moving iron instruments indicate the rms value of any ac waveform applied. One of the design objectives of the instrument is to disturb the circuit as little directly drive the hp highspeed digital. The iron van is so situated that it can move in the magnetic field produced by a stationary coil. A movingcoil permanentmagnet instrument can be used as fluxmeter. An alternator is an electrical machine which converts mechanical energy into alternating electric energy. As their name suggests, these are simple electromagnets, working rather like the moving coils that make sounds in loudspeakers. The platters are the most important parts of a hard drive. Working principle of electrostatic type instruments. The iron van is so situated that it can move in the. In moving iron instruments, a van of soft iron forms the moving element of the system. The instrument can be constructed to measure current and voltage to an accuracy needed in most engineering works and still be cheaper as compared any other type of a. The workpiece is situated on the stationary jaw before the moving jaw is lowered with a screw and pressure exerted. The instrument can be constructed to measure current and voltage to an accuracy needed in most engineering works and still be ch. In moving iron instruments the movable system consists of one or more pieces of speciallyshaped soft iron, which are so pivoted as to be acted upon by the magnetic field produced by the current in coil.
The force of attraction depends on the strength of the magnet field. Moving iron instrument working principle, construction, advantage. These instruments can measure current and voltage to a great accuracy. It operates on the principle that the torque is exerted on the moving coil placed in the field of the permanent magnet. A trip inside your electric iron history and theory of ironing. The moving iron instruments use the stationary coil of copper or aluminium wire which. The operating magnetic field in moving iron instrument is very weak. What is the difference between analog instruments and digital instruments. Movingiron measuring mechanisms are also used in ratio meters. Permanent magnet moving coil meter is used for only measuring dc quantity. Single phase induction type energy meter pdf to understand the basic construction and different components of a single phase induction type energy meter. Moving iron instruments are generally used to measure alternating voltages and currents. Hence moving iron instruments can be used for both a. A small hard drive typically has only one platter, but each side of it has a magnetic coating.
Ammeters, voltmeters are some of the examples of mi instruments. Permanent magnet moving coil or pmmc instrument definition. A magnetic stirrer or magnetic mixer is a laboratory device that employs a rotating magnetic field to cause a stir bar or flea immersed in a liquid to spin very quickly, thus stirring it. In the attraction moving iron instrument a specially shaped piece of soft iron with a pointer attached is pivoted near to the open end of a. Movingiron instruments construction and basic principle operation movingiron instruments are generally used to measure alternating voltages and currents. Working of ramp type dvm this is the block diagram of ramp type dvm. Questions and answers list eie south central railway. Jul 25, 2018 this instrument is one of the most primitive forms of measuring and relay instrument. Describe construction, working principle and applications of hall effect transducer. These instruments are based on the principle that when an unmagnetised soft iron piece is placed in the magnetic field of a coil, then the piece is attracted towards the coil. The working principle of an alternator or ac generator is similar to the basic working principle of a dc generator. Moving iron instruments construction and working principle in hindi duration. To study the construction and working of single phase energy meter and to find.
Apr 24, 20 principle construction and working of iron box wiki answers. The working of an electric iron is very simple it takes current from the mains and heats up a coil inside it. Moving iron instrument working principle, construction, advantage and. Basic meter movements can have fullscale deflection for currents from about 25 microamperes to 10. Construction and working of repulsion type moving iron construction and working of repulsion type moving iron. Basics, maintenance, and diagnostics vii contents continued page 4. In both the attraction and repulsion type movingiron instruments it is found that for a given position of the moving system, the value of the deflecting torque is proportional to the square of the current, so long as the iron is working below saturation. The moving iron instruments use the stationary coil of copper or aluminium wire which acts as an electromagnet when an electric current passes through it. The instrument in which the moving iron is used for measuring the flow of current or voltage is known as the moving iron instrument. The dimensionally stable synthetic diaphragm has the proven stadiumshaped form. A fixed vshaped lower jaw and a moving upper jaw hold lengths of pipe in place.
Movingiron instrument article about movingiron instrument. Steady state solution of dc circuits and problems based on ohms law. It can be designed to step up or step down voltages and works on the magnetic induction principle. As the name suggests the electrostatic type instrument use static electrical field to produce the deflecting torque.
Electrical test equipment used in mines with diagram. Repulsion type moving iron instrument working principle the basic principle of a repulsion type moving iron instruments is that the repulsive forces will act when two similarly magnetized iron pieces, are placed near each other. Jul 25, 2018 working principle of electrostatic type instruments. Optionally, the devices are available with no contact operation. The most widely used moving iron instruments are switchboard instruments of classes 1. Users can purchase an ebook on diskette or cd, but the most popular method of getting an ebook is to purchase a downloadable file of the. What is permanent magnet moving coil or pmmc instrument. Download basic electrical and electronics engineering notes pdf. Analog ammeter and voltmeter designed to measure a. This instrument is one of the most primitive forms of measuring and relay instrument. Moving iron mi instruments generally used to measure ac current or voltage but can measure dc current and voltage without any external circuit pointer is connected to specially designed soft iron that moves according to the intensity of magnetic field acting on it the magnetic field is produced by current carrying coil.
The basic working principle of these instruments is very simple that a soft iron piece if brought near the magnet gets attracted by the magnet. Moving iron instruments principle, operation and type. Quality, reliability and value for your lab making the best labs better. Moving iron instruments construction and basic principle operation moving iron instruments are generally used to measure alternating voltages and currents. The central focus is on packaged complete unit air compressors, most commonly used in sizes 30 horsepower and below as measured according to standards for continuous duty compressors. Course file on electrical measurements and instrumentation by ch. The relationship between an rtds resistance and the surrounding temperature is highly predictable, allowing for accurate and consistent temperature measurement. The instruments which use the permanent magnet for creating the stationary magnetic field between which the coil moves is known as the permanent magnet moving coil or pmmc instrument. Moving iron measuring mechanisms are also used in ratio meters. The patented slide control and the use of highgrade materials ensure a high quality standard. Moving iron instruments, classification of moving iron. As the name suggests, they are disks made from a hard material such as glass, ceramic, or aluminum, which is coated with a thin layer of metal that can be magnetized or demagnetized.
In most modern hard drives, voice coils are used instead. The construction of the attraction type instrument is shown in the fig. As laboratory standards from which working or inspection gauges are set and correlated. Figure below shows a simple moving iron instrument. The moving iron instrument uses the stationary coil as an electromagnet. The rotating field may be created either by a rotating magnet or a set of stationary electromagnets, placed beneath the vessel with the liquid magnetic stirrers are often used in chemistry and biology.
In a moving iron meter, the current to be measured flows through a flat coil as shown in fig. The moving system of the instrument is attached to the soft iron piece and the operating current is passed through a coil placed near it. It consist of a heating coil which gets heated and expanded when current passes through it viz. Moving iron instrument working operation electrical edition. Still mi instruments are cheap as compared to any other type of a. Ac synchronous generator alternator construction and. A basic transformer consists of two coils that are electrically separate and inductive, but are magnetically linked through a path of reluctance. A transformer has no moving parts and is a completely. Hi friends, in this article, i am discussing about moving iron instruments working principle and other necessary related information. The moving iron instruments or mi instruments are quite cheap in cost, simple in construction and very accurate at fixed power supply frequency. Moving iron type instruments are of mainly two types. To see other topics in basic electrical and electronics engineering click here.
Working principle of moving iron instruments electrical concepts. In movingiron instruments the movable system consists of one or more pieces of speciallyshaped soft iron, which are so pivoted as to be acted upon by the magnetic field produced by the. In movingiron instruments the movable system consists of one or more pieces of speciallyshaped soft iron, which are so pivoted as to be acted upon by the magnetic field produced by the current in coil. The strength of the magnetic field induces by the electromagnet is directly proportional to the current passes through it.
Ramp type dvm pdf dvm is essentially an analog to digital converter ad with a. Draw and explain the operation and principle of pmmc instrument. The main principle of operation of a transformer is mutual inductance between two circuits which is linked by a common magnetic flux. Calculation of resistance of shunts and multipliers to. Moving iron instruments free download as powerpoint presentation. In movingiron instruments the movable system consists of one or more pieces of speciallyshaped soft iron, which are so pivoted as to be acted upon by.
Electrostatic type instruments construction principle. Attached with some machines, comparators can be used as working gauges to prevent work spoilage and to maintain required tolerances at all stages of manufacturing. We have provided basic electrical and electronics of b. The magnetic field induces by the electromagnet whose strength depends. Apr 20, 2018 working principle of moving iron instruments. The latter instruments may be used for frequencies of up to 800 hertz. A guide to vises different types of vices and how they work. The principle of working of a pneumatic comparator is shown in figure 1. This heat is then transferred to the base plate which is pressed against clothes to remove creases. Electrostatic type instruments construction principle torque. Moving iron instruments principle, operation and type, theory.
Moving iron instruments moving iron instruments are the most common instruments used for measurements of electrical quantities. The rotating field may be created either by a rotating magnet or a set of stationary electromagnets, placed beneath the vessel with the liquid. Tech 1st year study materials and lecture notes for cse, ece, eee, it, mech, civil, ane, ae, pce and all other branches. Ueeneeg101a solve problems in electromagnetic devices. Elements of electrical technology, grades 11 and 12. Click here to download the pdf of this topic moving iron instruments. It works on the principle that when two pieces of soft iron rod or strips are magnetized in the same direction by the current carrying coil, they will.
Movingiron instruments are generally used to measure alternating voltages and currents. In both the attraction and repulsion type moving iron instruments it is found that for a given position of the moving system, the value of the deflecting torque is proportional to the square of the current, so long as the iron is working below saturation. Back when i was learning how to iron my clothes, i was rather annoyed by the whole process. Principle of operation of a resistance temperature detector rtd. The various ways in which the comparators can be used are. The force of this attraction depends upon the strength said magnetic field. The working principle of an electric iron science abc.
The model on the cover of the box was my mother margaret k stanley. Nevertheless, by making the fixed iron curved and tapering as shown in fig. The most widely used movingiron instruments are switchboard instruments of classes 1. Movingiron instruments construction and basic principle operation. Yoke vises, also known as hinged vises or adjustable jaw vices, use a screw to clamp the pipe in place. Sep 05, 2012 repulsion type moving iron instruments.
Jun 11, 2016 the working of an electric iron is very simple it takes current from the mains and heats up a coil inside it. It works on the principle that the iron place near the magnet attracts towards it. A hollow circular coil is used and one of the iron pieces is attached inside the hollow coil. An ammeter from ampere meter is a measuring instrument used to measure the current in a. Due to square low response, the scale of the moving iron instrument is nonuniform. The system synchronises the operation of the slides with the current flow through the measuring chamber thus enabling minimum slide cross sections. Once the door was opened, people decided that it was a whole lot of work and social trends. Equip your lab with more than 120 assays in one integrated system. Movingiron instruments physics homework help, physics.
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