Practical of calibration of voltmeter using potentiometer. Calibration of ammeter and voltmeter using potentiometer dr. Calibration of pmmc voltmeter and ammeter by dc cromptons potentiometer po1,po2, pso2,pso3. Conversion of voltmeter to ammeter and viceversa niser. It is a complete setup with training board, potentiometer and calibration unit. Laboratory manual basic electrical engineering laboratory.
This is done by adding a high resistance in series with the ammeter. For the most accurate measurement of resistance, the wheatstone bridge circuit is used. How to calibrate a voltmeter using a potentiometer kisembo academy. Experiment 3 ammeters and voltmeters flashcards quizlet. In this practical we will show you how to calibrate the voltmeter using a potentiometer. Potentiometer calibration of ammeter kisembo academy. Apr 05, 2018 a potentiometer can be used to calibrate a voltmeter by using a potentiometer to obtain a calibration curve for the voltmeter. This measured resistance rm will be the true value of the resistance if and only if the resistance of ammeter is zero and that of voltmeter is infinite. Ammeter ammeter is employed for measuring of current in a circuit and connected in series in the circuit.
The range of this meter is v imrm r where the multiplier resistance, r can be r 1 or r 2 or. Use a stable voltage source, preferably a variable voltage source or potentiometer to vary the c. We are required to calibrate the ammeter to know about its errors and adjust it to get near to ideal readings. Calibration of voltmeter and ammeter using potentiometer.
Measure the source current using the keithley 2000 and enter the current value on the data sheet. Multimeter, ammeter and breadboards in this lab we will become familiar with three instruments that you will use throughout the semester. Every measuring instrument basically measures quantity you want to measure and displays a reading which. The true value of current or voltage in the circuit can be measured up to a fair grade of accuracy by using a potentiometer. The actual voltage drop across the current coil of the voltmeter is only a fraction of the total voltage applied across the voltmeter which is to be measured. In this practical we will show you how to calibrate the ammeter using a potentiometer. In this video i explain the calibration of a voltmeter using a potentiometer. Accuracy of the basic meter or calibrate and display on the scale of the meter, for functional applications, like displaying a parameter with engineering units like rpm, kgcm2 or 0c etc. Pandey conversion of galvanometer to ammeter object. Potentiometer calibration of voltmeter kisembo academy. Converting an ammeter to a voltmeter involves increasing the resistance of the ammeter. Remove the voltmeter from the power supply and measure voltages across each of the resistors in the circuit. Not only ammeter or voltmeter, any measuring instrument needs to be precisely calibrated first before using it for any kind of measurement.
Jan 08, 2019 in both the cases, the reading of voltmeter and ammeter is taken. Apr 05, 2018 potentiometer, as the name says, measures potential. Range extension of ammeters voltmeters your electrical. Calibration of volt and ameter using potentiometer. In other words, calibration checks the correctness of. Imprecise ohmmeter made from galvanometer, series resistor, variable resistor, and a dc voltage source. A voltmeter is connected in parallel with a device to. Conversion of ammeter to voltmeter converting an ammeter to a voltmeter involves increasing the resistance of the ammeter.
To calibrate voltmeter and ammeter using potentiometer. Then as seen from figure, the voltage drop across r is v. Agilan bv physics practical in tamil potentiometer calibration of low. To calibrate the given ammeter by using potentiometer. We are required to calibrate the voltmeter to ideal readings. In ammeter designs, external resistors added to extend the usable range of the movement are connected in parallel with the movement rather than in series as is the case for voltmeters. Demonstration of various instruments like ammeter, voltmeter, wattmeter, energy meter, tachometer, rheostat, various capacitors, various resistors, ac and dc power supply. As mentioned above, we will use a suitable stable dc supply voltage to avoid the errors in calibration which do not produce voltage fluctuations during the entire experiment.
Experiment 4 experiment 4 voltmeter and ammeter tuesday. Calibration of dynamometer wattmeter using phantom loadingupf. It is because the division of current between the operating coil and the shunt varies with frequency since reactance of the coil depends upon. The facility to connect external wattmeter or voltmeter and ammeter is also provided. This experiment will guide students through making a labmade voltmeter and ammeter using a galvanometer and resistors. Lendi institute of engineering and technology approved by a.
Experiment 4 voltmeter and ammeter tuesday, september 15 th, 2015 phy2049l dr. Measurement of power by 3voltmeter and 3ammeter methods. You should have a total of two sets raw data tables by the end of this part. Calibration of ammeter, voltmeter, and wattmeter using potentiometer. The best method of calibration is to measure the true value of current or voltage in the circuit and compare it with the value measured by the given ammeter or voltmeter.
A meter designed to measure electrical current is popularly called an ammeter because the unit of measurement is amps. Potentiometer calibration of pmmc ammeter and pmmc voltmeter 4. Polar formcartesian form calibration of ac voltmeter, parameters of choke. Viva voce on galvanometer to ammeter or voltmeter q. Ii electronic voltmeters and ammeters alessandro ferrero, halit eren encyclopedia of life support systems eolss when a voltmeter is configured, different fullscale values can be obtained by using selectableratio voltage dividers if the input voltage is higher than the amplifier dynamic range. An ammeter is a device used to measure the current, that is the the. Sigmas calibration lab presents electrical calibration which offers voltmeter calibration and multimeter calibration. The accuracy of an analog ammeter or voltmeter is usually stated as a. A galvanometer is an instrument used to detect and measure small electrical currents. To learn how to determine uncertainty of meter readings. Potentiometer, as the name says, measures potential. Calibration of ammeter and voltmeter free download as word doc. A rheostat is used for adjusting the magnitude of the current flowing through the entire circuit.
Calibration unit has a voltmeter and an ammeter, which can be calibrated by potentiometer. For the conversion of galvanometer to ammeter ga a low resistance shunt resistance s is. Turn on the power supply and adjust it so that the output is 12v as measured on the fluke 45. Calibration of dc ammeter and dc voltmeter students room. For an ammeter you should measure its internal resistance or impedance if it is ac ammeter. Why is it necessary to calibrate an ammeter and a voltmeter.
In other words, calibration checks the correctness of the instrument by comparing it with the reference standard. The potentiometer is used extensively for the calibration of voltmeters and ammeters, and provides a standard method for calibration of these instruments. The experiment is repeated for different values of load current at constant. Ammeter design dc metering circuits electronics textbook. Calibration of voltmeter and ammeter by potentiometer is an elite setup designed to understand the functioning and calibration of potentiometer, voltmeter and ammeter. Learning how to use those meters and using them to measure the current, voltage, and resistance of an electric circuit. The experiment is repeated by varying the curden and setting different values for iss. As we know, wattmeters are used for measurement of power in inductance ac circuits, but in some cases it is not possible to use wattmeters because of their incorrect readings or sometime wattmaters may not available.
This circuit avoids most of the difficulties of the ammetervoltmeter method. To calibrate and testing of single phase induction type energy meter. A voltmeter is an instrument used for measuring electrical potential difference between two points in an electric circuit. Voltmeter connected to battery and reading obtained resistance box added and circuit is adjusted so that voltage reading is 12 of former value current in second case is half current in first case total voltage is the same voltmeter resistance is the same as added resistance. If the voltmeter reading is v and ammeter reading is i then the measured resistance will be. To calibrate an ammeter, you need a 1 ohm reference shunt resistor or accurately measured shunt of low resistance in series with the meter and measure the voltage drop across the shunt with a potentiometer and calculate the current. So in such cases three voltmeters or three ammeter method is used continue reading three voltmeter method. Calibration of voltmeter using dc potentiometer calibration of ammeter using dc potentiometer apparatus required. Calibration of ammeter and voltmeter using potentiometer. It is a device which measures the presence of current in circuit.
The resistance of voltmeter is kept very high by connecting a high resistance in series of the voltmeter with the current coil of the instrument. You need a calibrated and certified ammeter, certified by a standard or recognized calibration laboratory, which covers the required current range. Instrumentation and oscilloscope introduction part 1. Calibration of the converted ammeter converted ammeter standard ammeter correction. Measurement of 3 phase power with single watt meter and 2 nos of c. Multirange voltmeter a multirange voltmeter consists of a deflection instrument, several multiplier resistors and a rotary switch. Conversion of voltmeter to ammeter and viceversa objective.
Learning how to use those meters and using them to measure the current, voltage, and. Measurement of parameters of a choke coil using 3 voltmeter and 3 ammeter methods. Potentiometer calibration of ammeter kisembo academy youtube. An ammeter is a measuring device used to measure the electric current in a circuit. Note that you need to have precise equipment for this, as currents flowing through a voltmeter are microampers, and voltage drops on ammeters are at most milivolts in typical solutions. Get the signature on experiment result sheet daily.
The instrument is based on the idea that when current flows through a wire, a magnetic field is produced. Calibration of single phase energy meter using phantom loading method with rss meter as standard 2. Calibration of ammeter and voltmeter electrical engineering. Let the range of the ammeter be 0 i0 amp and we convert it to a voltmeter of range 0 v0 volt. No name of the experiment 1 calibration and testing of single phase energy. Voltmeters and ammeters are used to measure voltage and current, respectively. This is a null method, in which no meter reading needs be taken except for a judgment of when the deflection of a galvanometer has been reduced to zero. Multimeter measurements on dc resistive circuits objectives. We are required to calibrate the ammeter to know about its. Calibration of ammeter, voltmeter, and wattmeter using. Understanding the structure of the ammeter, voltmeter, and ohmmeter. Oct 29, 2010 to calibrate voltmeter and ammeter using potentiometer set up of the apparatus is arranged in circuit. How you can do calibration of voltmeter by potentiometer.
The instrument that used to be called a potentimeter was a rheostat and a galvanometer movement, a voltage reference and a momentary contact. The calibration is the process of checking the accuracy of the result by comparing it with the standard value. Demonstration of various instruments like ammeter, voltmeter. Mar 23, 2018 you need a calibrated and certified ammeter, certified by a standard or recognized calibration laboratory, which covers the required current range.
Introduction to various supply systems, ammeter, voltmeter, wattmeter, energy meter, tachometer, rheostat, loading devices, transformer. In other words, calibration checks the correctness of the instrument by comparing it. Now the ammeter which converted to a voltmeter should have the full scale read out when 5 volt is connect to it. The following experiments are required to be conducted as compulsory experiments. Watch this video to know more about calibration of voltmeter.
To convert weston galvanometer to a ammeter of current range 0 to a amp. Calibrating ac voltmeters and ammeters for different fullscale ranges of operation is much the same as with dc instruments. Inbuilt voltmeter, ammeter, wattmeter as standard meter for. An ammeter is a low impedance device that measures the current going through a circuit, often by measuring the small voltage across a known resistance. To calibrate voltmeter and ammeter using potentiometer answers. This circuit avoids most of the difficulties of the ammeter voltmeter method. This approach assumes the ammeter has zero internal resistance. Repeat the entire experiment, but this time with a slight variation to the circuit as shown in figure 3b. Verification of ohms law using ammeter and voltmeter posted on march 22, 20 by shah jamal ohms law states that the current through a conductor between two points is directly proportional to the potential difference across the two points.
Measurement of power by using 3 voltmeter and 3 ammeter methods. To calibrate voltmeter with potentiometer physics practical. Measurement of voltage, current, and resistance using the multimeters provided in the lab. Conversion of galvanometer to ammeter home page of. The complete set up consists of two energy meters, wattmeter, voltmeter. Mar 22, 20 verification of ohms law using ammeter and voltmeter posted on march 22, 20 by shah jamal ohms law states that the current through a conductor between two points is directly proportional to the potential difference across the two points. When a current flows through it then torque acts on it. Calibration of voltmeters and ammeter by potentiometer 2. Nvis 6032 calibration of voltmeter and ammeter by potentiometer is an elite setup designed to understand the functioning and calibration of potentiometer, voltmeter and ammeter.
So in such cases three voltmeters or three ammeter method is used for measurement of power. In both the cases, the reading of voltmeter and ammeter is taken. Taking the same meter movement as the voltmeter example, we can see that it would make a very limited instrument by itself, fullscale deflection occurring at. To study and perform calibration of ac voltmeter and ac ammeter objective. Electrical measurements lab manual pdf em lab manual pdf. The following sections describe a number of common requirements for calibration of electrostatic measuring instruments. Verification of ohms law using ammeter and voltmeter. Shunts can not be used to extend the range of movingiron ac ammeters accurately.
904 978 653 529 261 961 1250 961 1141 1465 255 138 303 428 1242 1514 1167 1253 870 182 923 864 1056 971 888 215 1480 61 895 979 1430