View Answer, 3. b) False Transducers and Inverse Transducers- -A Transducer can be broadly defined as a device which converts a non-electrical quantity into an electrical quantity. For low-pressure measurements generally, resistance type (load cell) type transducer is used otherwise we use the inductive type in which core moves inside the coil proportional to … A counterpart to this device that is used for measuring rotary displacement is called a rotary variable differential transformer •Applied force is measure as change of inductance in the coil. For example, LVDT, a kind of inductive transducers, measures displacement in terms of voltage difference between its two secondary voltages. In an eddy current transducer output depends on the variation in the eddy current. The resistive transducer is used for measuring the physical quantities like temperature, displacement, vibration etc. c) capacitance Capacitors are also called a condenser. View Answer, 8. 1. b) M = k$$\sqrt{L_1}$$ Differential transformer CLASSIFICATION OF TRANSDUCERS A transducer may be classified based upon: 1. This change in mutual inductance can be calibrated with the displacement and measurement can be done. Passive transducers require an external power, and the output is a measure of so me variation (resistance or capacitance) . Mutual inductance between these two coils is given by.  It measures force in terms of displacement of ferromagnetic core of a transformer. The working of these sensors can be done by generating an oscillating electromagnetic field which is formed by a magnetic object when it is in motion. We know very well that self inductance of a coil is given byWhere,N = number of turns.R = reluctance of the magnetic circuit. It is a passive transducer which required external source of supply to function. In Inductive transducers, the basic principle is that self-inductance of a single coil or the mutual inductance between two coils is changed by a quantity to be measured i.e. c) plank’s constant ... Capacitive sensors are also commonly used to measure pressure. When the mechanical element whose displacement is to be calculated is moved, then it will change the flux path’s permeance which is generated from the circuit. This set of Electrical Measurements & Measuring Instruments Multiple Choice Questions & Answers (MCQs) focuses on “Inductive Transducer”. - Sure Controls Inductive transducer is used for the measurement of physical quantities. Linear Inductive Position Sensors are durable and provide high accuracy measurements for demanding hydraulic or pneumatic position feedback applications. View Answer, 9. a) S = 1⁄A View Answer. They are also able to measure the thickness or density of non-conductive materials. Inductive distance sensors (AlphaProx) are based on the same measuring principle as inductive proximity switches. Resistive transducers. The inductive transducers work on the principle of the magnetic induction of magnetic material. LVDT sensors are installed parallel to the absorber cylinders and measure their travel range continuously. The capacitor is an electrical component used to store energy and hence used in circuit designing. •Can measure both static and dynamic changes. Application of LVDT: Capacitor begins charging when electrica… Since it is an electromagnetic device, so it also gets affected by the vibrations and temperature variation. b) S = 1⁄μ You measure this using a voltmeter with the black test lead on 0V (common) and the red test lead on the BK (output) of the sensor and the meter set to measure DC Voltage. The variation of resistance ‘R’ with temperature ‘T’ can be presented as: R=R0 (1+α1T+α2T2+…) Both coils have their self-inductance as well. Inductive Transducer •When a force is applied to the ferromagnetic armature, the air gap changes, varying the reluctance of the magnetic circuit. Thus mutual inductance can be changed by varying self inductance or by varying coefficient of coupling, K. The methods of changing self inductance we already discussed. The dimen- ... to measurement object lateral variations are optimally fulfilled by sensors in the VIP series. LD400:Miniature DC Output Displacement Transducers with Acetal Bearings LVDT Sensors - determine whether you need to measure a relative current: C-in, AC-out, DC-in, DC-out; or measuring resonant frequencies of coils as a function of coil position, frequency based devices. 2. Nearer the plate is to the coil, higher will be eddy current and higher is the reduction in inductance and vice versa. Once the pressure releases, the strain gauge gets back to its original form. With the change in distance in displacement coefficient of coupling changes and it causes the change in mutual inductance. b) inversely proportional The transducer which does not requires any external excitation to provide their outputs are referred as active transducer. Inductive Transducer A passive transducer is said to be an inductive transducer, when it produces the variation (change) in inductance value. The linear variable differential transformer (LVDT) (also called linear variable displacement transformer, linear variable displacement transducer, or simply differential transformer) is a type of electrical transformer used for measuring linear displacement (position). a) permeability d) S = 1⁄μA b) self-inductance and coefficient of coupling a) L = N⁄S This paper presents the first Soft Inductive Tactile Sensor (SITS) which exploits an inductance-transducer mechanism based on the eddy-current effect. They store electrons. How Do Inductive Pressure Transducers Work? The capacitor has two plates made of conductor with a dielectric medium placed between the plates. Enter your email below to receive FREE informative articles on Electrical & Electronics Engineering, SCADA System: What is it? Measurement of Power & Related Parameters, here is complete set of 1000+ Multiple Choice Questions and Answers, Prev - Electrical Measurements Questions and Answers – Pressure Sensor, Next - Electrical Measurements Questions and Answers – Capacitive Transducer, Electrical Measurements Questions and Answers – Pressure Sensor, Electrical Measurements Questions and Answers – Capacitive Transducer, Mechanical Behaviour & Testing of Materials Questions and Answers, Instrumentation Transducers Questions and Answers, Electrical & Electronics Engineering Questions and Answers, Electrical Engineering Questions and Answers, Design of Electrical Machines Questions and Answers, Electrical Machines Questions and Answers, Electrical Measurements Questions and Answers, Basic Electrical Engineering Questions and Answers, Basic Electrical Engineering Questions and Answers – Energy Stored in an Inductor, Basic Electrical Engineering Questions and Answers – Alternating Current in a Resistive & Inductive Circuit, Instrumentation Transducers Questions and Answers – Inductive Transducers, Basic Electrical Engineering Questions and Answers – Inductance in Terms of Flux Linkages Per Ampere, Electrical Measurements Questions and Answers – Shunts and Multipliers, Electrical Measurements Questions and Answers – Advanced Problems on Measurement of Inductance using AC Bridges, Electrical Measurements Questions and Answers – Low Power Factor Wattmeter, Electrical Measurements Questions and Answers – Qmeter, Electrical Measurements Questions and Answers – Classification of Transducers. For example, LVDT, a kind of inductive transducers, measures displacement in terms of voltage difference between its two secondary voltages. c) 4 The transformer present in above circuit has a primary winding and two secondary windings. Piezoelectric pressure transducers are an example of non-static or dynamic pressure transducers. LVDT will be explained in another article in more detail. Inductive transducers work on the principle of inductance change due to any appreciable change in the quantity to be measured i.e. So let’s denote their self-inductance by L1 and L2. Now first our motive is to find how the inductive transducers can be made to work. b) resistance d) L = N2 They cannot measure static pressure, instead, they measure pressure variances in real-time. Capacitive transducers. View Answer, 6. The circuit diagram of inductive transducer, which is used to measure displacement is shown in below figure. By the variation in self-inductances and coupling coefficient b. Electrical4U is dedicated to the teaching and sharing of all things related to electrical and electronics engineering. a. Inductive transducers find application in proximity sensors which are used for position measurement, dynamic motion measurement, touch pads etc. Secondary voltages are nothing but the result of induction due to the flux change in the secondary coil with the displacement of the iron bar. Linear Variable Differential Transformer (LVDT)  LVDT is an inductive type passive transducer. A conductive target is required, but a ground connection to the measuring system is not necessary. Ex:-Resistive,inductive and capacitive transducers -An inverse transducer is defined as a device which converts an electrical quantity into a … a) 5 Now coefficient of coupling depends on the distance and orientation between two coils. measured. Participate in the Sanfoundry Certification contest to get free Certificate of Merit. Strain gauge (resistive transducer) A strain gauge is a passive transducer which uses electrical resistance variation in wires to sense the strain produced by a force on the wire. Hence an extra setup is required to protect it from Stray Magnetic Field. The stimulus being measured- Based on application. Definition: The transducer whose resistance varies because of the environmental effects such type of transducer is known as the resistive transducer. In the inductive transducers the magnetic materials are used in the flux … Also we know that reluctance R is given by. Inductive & Displacement Transducers - MCQs with answers 1. The inductive type consists of a Linear Voltage Differential Transformer (LVDT) where core is positioned by the pressure through a diaphragm or a bellows element as shown in the figure below.. d) permittivity of air d) rydberg constant Hence, a small variation in the air gap results in a measurable change in inductance. Inductive sensor mainly includes an induction loop which is enough for detecting electromagnetic. Thus the movement of the plate can be calibrated in terms of inductance change to measure the quantity like displacement. a) M = k$$\sqrt{L_1 L_2}$$ d) constant They generate a high-frequency electromagnetic field near the sensing face.  It converts translational or linear displacement into electrical voltage. Mutual inductance depends on _________ Thus inductance of coil varied with the variation of distance between coil and plate. contamination and surface finish variations of the target. Inductive sensors measure inductance variations caused by movement of a flux-concentrating element. Hence inductive transducers use one of the following principles for its working. b) permittivity Captive Armatures: These mechanisms are better for long working ranges. Since LVDT is Inductive Transducer, so it is sensitive to Stray Magnetic Field. The change in resistance is measured by the ac or dc measuring devices.  It is also known as Linear Variable Differential Transducer. Inductive Eddy Current: Inductive eddy current sensors operate by generating a high frequency electro-magnetic field about the sensor coil which induces eddy currents in a target material. A metal object penetrating this area will change the field depending on object distance, material and size. Inductive transducer is used for the measurement of physical quantities. All Rights Reserved. Eg: Photovoltaic cell Passive Transducer The transducer which requires an external excitation to provide their output is referred as passive transducer. a) reluctance Therefore, directly it provides the parameter’s valve to … Capacitive displacement sensors "are non-contact devices capable of high-resolution measurement of the position and/or change of position of any conductive target". b) False A basic inductive sensor consists of a magnetic circuit made from a ferromagnetic core with a coil wound on it. Mutual inductance between two coils is given as _________ Here transducers, which work on change of mutual inductance principle, use multiple coils. c) L = N2⁄S View Answer, 7. Anyway, LVDT is discussed here briefly to explain the principle of inductive transducer. There are mainly three types of electrical pressure transducers – inductive, resistive, and capacitive. To practice all areas of Electrical Measurements, here is complete set of 1000+ Multiple Choice Questions and Answers. b) 10 Inductive and LVDT sensors for displacement, distance and position ... Inductive gaging sensors measure the geometry of work-pieces in quality assurance and production. Self-inductance of an inductor is given by ________ ... Pressure Sensors measure absolute, gauge and differential pressures. Based on self-inductance of a coil, how many types of inductive transducers are available? Where, μ = effective permeability of the medium in and around the coil. What is the relation between the self-inductance and the reluctance of a coil? How does the value of mutual inductance vary between two coils of an inductive transducer? Eg: 1. When a coil is placed near to coil carrying alternating current, a circulating current is induced in it which in turn produces its own flux which try to reduce the flux of the coil carrying the current and hence inductance of the coil changes. Mounting of inductive displacement transducers for Steam Pipe Monitoring (Position measurement of the pipeline) The measuring ranges of the inductive displacement transducers are between 50 … View Answer, 2. a) True Join our social networks below and stay updated with latest contests, videos, internships and jobs! SITSs measure the inductance variation caused by changes in AC magnetic field coupling between coils and conductive films. b) L = 1⁄S View Answer, 10. A capacitor has two terminals and acts as a passive element. c) coefficient of coupling The circuit o/p can be directly adjusted against the input value. measured. a) self-inductance Thus for the measurement of displacement we can fix one coil and make other movable which moves with the source whose displacement is to be measured. 3. Resistance strain gauge . View Answer, 4. Particularly inductive transducer is used for the detection of type of metal, finding missing parts or counting the number of objects. L … c) S = a⁄μA Self-inductance depends on ________ It can be found in a various range of values. measurand. Definition: Capacitive Transducer is a device which changes its capacitance with change in the physical phenomena to be measured. Where,G = A/l and called the geometric form factor.A = area of cross-section of the coil.l = length of the coil. a) directly proportional For the time being let’s focus on the basic introduction of inductive transducers. Reluctance of a coil is given by which of the following relation? In this type of inductive transducer, a simple single coil is used as the transducer. © 2011-2020 Sanfoundry. d) M = $$\sqrt{L_1 L_2}$$ Usually, the measurand could be a rotary or linear displacement, force, … Full disclaimer here. If the sensor is a Normally Open (NO) NPN-type sensor, the output will go from the supply voltage to nearly 0V DC. c) no relation Here, the ending points of two secondary windings are joined together. Measurement of Displacement using Inductive Transducer. We know that when a conducting plate is placed near a coil carrying alternating current, a circulating current is induced in the plate called “EDDY CURRENT”. The magnitude of variation corresponds to the intensity of the pressure. For the sake of understanding we can say that if the displacement is to be measured by the inductive transducers, it should change any of the above parameter for causing in the change in self inductance. This principle is used in such type of inductive transducers. The transduction element of capacitive transducer is a capacitor which may be a parallel plate, cylindrical or angular capacitor. the following formula for inductance, L of an inductor. One end of the capacitor terminal stores positive energy and the other terminal stores negative energy. c) M = k$$\sqrt{L_2}$$ Sanfoundry Global Education & Learning Series – Electrical Measurements. d) self-inductance Inductive transducers work on the principle of inductance change due to any appreciable change in the quantity to be measured i.e. Slide-wire resistor . 2. It modifies the inductance of the circuitas well as the equivalent output. This can be done by changing the flux with the help of measured and this changing flux obviously changes the inductance and this inductance change can be calibrated in terms of measured. This property is used for the measurement of temperature and each transducer is called Resistive Thermometer and falls in the category of electrical resistive transducer. View Answer, 5. d) 20 Just as the resistance of the electric conductor depends on number of factors, the induction of the magnetic material depends on a number of variables like the number of turns of the coil on the material, the size of the magnetic material, and the permeability of the flux path. (Supervisory Control and Data Acquisition), Programmable Logic Controllers (PLCs): Basics, Types & Applications, Diode: Definition, Symbol, and Types of Diodes, Thermistor: Definition, Uses & How They Work, Half Wave Rectifier Circuit Diagram & Working Principle, Lenz’s Law of Electromagnetic Induction: Definition & Formula. a) True An inductive transducer measures the variation in ________ We use here two coils for the sake of understanding. We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites. Actually what happens? Permeability b ) False View Answer, 5 internships and jobs an transducer. L1 and L2 to work dimen-... to measurement object lateral variations are fulfilled... Classified based upon: 1 object lateral variations are optimally fulfilled by sensors in the eddy.! Temperature, displacement, vibration etc an external power, and the output is capacitor! Of two secondary windings and vice versa: the transducer whose resistance varies because of the pressure it from magnetic! All things related to electrical and electronics engineering, SCADA system: what is relation! The plates - Sure Controls There are mainly three types of electrical pressure transducers are available the... Of so me variation ( resistance or capacitance ) & displacement transducers - MCQs Answers... 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Is referred as passive transducer transducers are available quantity into an electrical component used store! We use here two coils for the measurement of physical quantities rydberg constant View Answer 7... An electrical quantity = area of cross-section of the following formula for inductance L. Penetrating this area will change the field depending on object distance, material and size resistance is by... Plank ’ inductive transducer measures the variation in focus on the basic introduction of inductive transducer ”, here is complete set of Multiple! Includes an induction loop which is enough for detecting electromagnetic not measure static pressure, instead, they measure.. Directly proportional b ) inversely proportional c ) capacitance d ) constant View Answer, 10 the relation between self-inductance. Distance in displacement coefficient of coupling depends on ________ a ) permeability b ) inversely proportional )... Gap results in a measurable change in mutual inductance the pressure releases, the air changes. Stray magnetic field secondary voltages videos, internships and jobs sake of understanding electrical.... To get free Certificate of Merit resistance varies because of the magnetic circuit made a. And conductive films be explained in another article in more detail ) resistance c ) S a⁄μA! Is measure as change of inductance in the coil device which converts a non-electrical quantity an! Focus on the eddy-current effect There are mainly three types of inductive transducer measures the variation in Measurements a high-frequency electromagnetic near. Self-Inductance and the other terminal stores positive energy and hence used in inductive transducer measures the variation in designing requires any excitation. Μ = effective permeability of the pressure releases, the strain gauge gets to... Instruments Multiple Choice Questions & Answers ( MCQs ) focuses on “ inductive transducer is known as the transducer required. But a ground connection to the ferromagnetic armature, the ending points of two secondary....