Pakistan Navy Engineering College (NUST)PAKISTAN NAVY ENGINEERING COLLEGE, NATIONAL UNIVERSITY OF SCIENCES AND TECHNOLOGY, KARACHIPNEC NUST

INSTRUMENTATION & MEASUREMENTEL-314

Lab Manual

UNIFIED CURRICULA 2012

PNEC, PNS JUAHER, HABIB REHMATULLAH ROAD, KARACHI 75350

EL-314 INSTRUMENTATION & MEASUREMENTLAB CONTENTSS No.ObjectivesRemarks

1To understand the internal architecture of analog multi meter and reading the measurements3

2To construct the Volt Meter using PMMC for different ranges.3

3To construct the Ammeter using PMMC for different ranges.3

4To construct the Ohm Meter using PMMC for different ranges.3

5To construct the digital event counter for 4bit and 8bit decimal counting.3

6To construct time base for digital frequency counter for 1ms , 10ms, 100ms and 1s.6

7Using the event counter (experiment#5), make the digital frequency counter with selectable time base.3

8To construct a resistive bridge circuit for receiving the proportional differential output voltage against a sensor (use LDR, PT-100, thermistors , thermocouple etc as sensor)6

9Use LVDT in a bridge circuit to measure the displacement and display the proportional voltage.3

10Using the bridge in experiment#8 measure/ display the output voltage with the help of a differential ADC.6

11To construct a Digital volt meter using ICL7106/ ICL71073

12To understand and analyze signals on oscilloscope and spectrum analyzer.3

13Mini Projects9

Experiment # 1

Objective: To investigate the internal architecture of analog multimeter and reading the measurementTHEORY:Basic parts of a permanent-magnet moving coil meter

Schematic DiagramB.Pictorial DiagramAnalog multimeters are the PMMC instruments as they use a pointer and the calibrated scale to indicate the values.They consist of a coil of a wire (copper wire) suspended in the field of permanent magnet. A pointer is attached on the coil, current is passed through the coil to produce a magnetic field that interacts with the field from magnet, resulting in the partial rotation of the coil. A pointer connected to the coil deflected over a calibrated scale, indicating the level of current flowing in the wire. i.e

D ID=BLIND

Where,B = Magnetic Flux Density (Tesla)L = Length of coil (meter)I = Current in the coil (Amperes)N = Number of turns of coilD = Diameter of coilThree forces are operating in the electromechanical mechanism inside the instrument:The deflecting force causes the pointer to move from its zero position when a current flows. As the current flows, a magnetic field is set up, which interacts with the field of the permanent magnet. Hence, a force is exerted on the coil turns, causing the coil to rotate on its pivots. The pointer is fixed to the coil, so it moves over the scale as the coil rotates.The controlling force in the PMMC instrument is provided by spiral springs. The springs retain the coil and pointer at their zero position when no current is flowing. When the current flows, the springs wind up as the coil rotates and the force they exert on the coil increases. The coil and pointer stop rotating when the controlling force becomes equal to the defecting force.The pointer and the coil tend to oscillate for some time before settling down at their position, hence a damping force is required to minimize the oscillations. The damping force is provided by eddy currents. Eddy currents induced in the coil former (made of aluminium)set up a magnetic field that opposes the coil motion, thus damping the oscillations of the coil. Without rectifier it is purely a DC instrument. The PMMC instrument is a low level ammeter but with the use of parallel connected resistors, it can be employed to measure a wide range of direct current levels. The instrument may also be made to function as a Dc voltmeter by connecting appropriate value resistors in series with it. Analog Multi-meters:

Figure 2 : An Analog Multi-meter

An analogue meter moves a needle along a scale. Switched range analogue multi-meters are very cheap but are difficult for beginners to read accurately, especially on resistance scales. The meter movement is delicate and dropping the meter is likely to damage it! Each type of meter has its advantages. Used as a voltmeter, a digital meter is usually better because its resistance is much higher, 1 M or 10M, compared to 200 K for an

analogue multi-meter on a similar range. On the other hand, it is easier to follow a slowly changing voltage by watching the needle on an analogue display. Used as an ammeter, an analogue multi-meter has a very low resistance and is very sensitive, with scales down to 50A. More expensive digital multi-meters can equal or better this performance. Most modern multi-meters are digital and traditional analogue types are destined to become obsolete.

Resolution of analog multi-meters is limited by the width of the scale pointer, parallax, vibration of the pointer, the accuracy of printing of scales, zero calibration, number of ranges, and errors due to non-horizontal use of the mechanical display. Accuracy of readings obtained is also often compromised by miscounting division markings, errors in mental arithmetic, parallax observation errors, and less than perfect eyesight. Mirrored scales and larger meter movements are used to improve resolution; two and a half to three digits equivalent resolution is usual (and is usually adequate for the limited precision needed for most measurements).

Resistance measurements, in particular, are of low precision due to the typical resistance measurement circuit which compresses the scale heavily at the higher resistance values. Inexpensive analog meters may have only a single resistance scale, seriously restricting the range of precise measurements. Typically an analog meter will have a panel adjustment to set the zero-ohms calibration of the meter, to compensate for the varying voltage of the meter battery.

TASK:Build the following circuit and measure the voltage and current across each component with the help of analog multimeter.

CALCULATIONS:

CONCLUSION:

Experiment # 2

Objective: To investigate and construct a dc-ammeter by using PMMC instrumentTHEORYMany dc meters use the DArsonval (PMMC) meter movement which measures current. The addition of a series resistance allows the measurement of voltage. The addition of a battery allows the measurement of resistance.Many direct-current ammeters and voltmeters are designed to measure current and voltage by making use of the well-known fact that when a current-carrying conductor is placed in a magnetic field, a force is exerted on the conductor. Furthermore, the force is directly proportional to the current. The way direct-current ammeters and voltmeters make use of this interaction between the magnetic field and the current is best described with the aid of the diagrams in Figure. The current to be measured is passed through the movable coil, where it reacts with the magnetic field of the permanent magnet, thus creating a torque on the coil. The coil rotates until the torque on it is balanced by the restoring spring. This spring is designed so that its torque is directly proportional to the angle through which the coil rotates, and the uniform magnetic field is oriented so that the force on the coil is always perpendicular to its axis. Thus, the deflection of the pointer is directly proportional to the current in the movable coil. The numerical value of the current is read from a calibrated scale placed at the end of the pointer.

CIRCUIT DIAGRAM:

TASK:Design the circuit by taking different values of Rshunt and tabulate the measured values.OBSERVATION TABLES.NORSVmvoltsRmImamperesIsamperesITamperes

1.

2.

3.

4.

CALCULATIONS:

CONCLUSION:

Experiment # 3

Objective: To investigate and construct a dc-voltmeter by using PMMC instrumentTHEORY: The deflection of a PMMC instrument is proportional to the current flowing through the moving coil. The coil current is directly proportional to the voltage across the coil. Therefore, the scale of the PMMC meter could be calibrated to indicate voltages. The coil resistance is normally quite small, and thus the coil voltage is also usually very small. Without any additional series resistance the PMMC instrument would only be able to measure very low voltage levels. The voltmeter range is easily increased by connecting a resistance in series with the instrument (as shown below in circuit diagram). Because it increases the range of voltmeter, the series resistance is termed a multiplier resistance. The PMMC instrument can be converted into a DC voltmeter by adding a series resistance (multiplier).

CIRCUIT DIAGRAM:

Im Rm=500

Im= full scale deflection current of the movementRm= internal resistance of movementRmultiplier= multiplier resistanceV=full range voltage of the instrument

From the circuit:-V + Im (Rmultiplier + Rm) =0Im (Rmultiplier + Rm) = V

Rmultiplier = Rm

TASK # 01:Design and implement voltmeter of ranges 1 volt, 10 volt, 14.7 volts, 30 volts. Also find out values of Rs. OBSERVATION TABLE:

TotalRmultiplierMovementE

I

R

CALCULATIONS:

TASK # 02:Design a multi range voltmeter 0f 1V, 3V,10V, 15V. OBSERVATION TABLE:

TotalRmultiplierMovementE

I

R

CALCULATIONS:

CONCLUSION:

Experiment # 4

Objective: To construct the ohmmeter using PMMC for different rangesTHEORY: The simplest ohmmeter circuit consists of a voltage source connected in series with a pair of terminals, a standard resistance and a low current PMMC instrument.The resistance to be measured (Rx) is connected across terminals A & B.If R1 (standard resistance) are selected (or if R1 is adjusted) to give FSD when A and B are short circuited, FSD is marked as zero ohms.When terminals A and B are open circuited, the effective value of resistance Rx is infinity. No meter current flows, and the pointer indicates zero current. This point (zero current) is marked as infinity () on the resistance scale.If a resistance Rx with a value between zero and infinity is connected across terminals A and B, the meter current is greater than zero but less than FSD. The pointer position on the scale now depends on the relationship between Rx and R1+Rm.Ohmmeter With Zero Adjustment:When the battery voltage falls, the instrument scale is no longer correct. Falling battery voltage can be taken care of by an adjustable resistor connected in parallel with the meter. The battery current splits up into meter current Im and resistor current I. with terminals A and B short circuited, R2 is adjusted to give FSD on the meter. Each time the ohmmeter is used, terminals A and B are first short circuited and R2 is adjusted for zero-ohm indication on the scale (i,e for FSD). If this

procedure is followed, then even when the battery voltage falls below its initial level, the scale remains correct. Rx+R1+(R2Rm)Equations:Basic Circuit:Rx = (R1+ Rm)At Rx = 0, Im =

Ohmmeter With Zero Adjustment:Ib = Where,Rx = Resistance to be measuredR1 = Standard ResistanceRm = Meter ResistanceEb = Battery voltage

Circuit Diagram:Basic Circuit:

Resistance to be measured

BAEbMeter Movement Standard ResistanceBattery RmR1RX

G

Ohmmeter With Zero Adjustment:

IbRXZero control RmR2Meter Movement R1BAEbBatteryG

Task # 01:First open circuit the terminals A and B, and show that Im = 0A. then find Rx at 0.5IFSD, 0.75IFSD,0.25IFSD.OBSERVATIONS:

CALCULATIONS:

TASK # 02:a) Set R2=Rx=0,see that full scale deflection occurs.b) Set Rx=0, and adjust R2, so that full scale deflection occurs.c) Find Rx at 0.5IFSD,0.25IFSD,0.75IFSD..OBSERVATIONS:

CALCULATIONS:

Conclusion:

Experiment # 5

Objective: To construct the digital event counter for 4bit and 8bit decimal countingTHEORY:The digital event counter measures the number of events of a particular sort occurring in a set period of time. I.C MM74C926 is commonly used for this purpose. It is a 4 digit counter with an internal output latch. Seven segment display (common cathode) is used to display the number of pulses.

LOGIC DIAGRAMS:

TASK:Use MM74C296 IC as digital event counter to count the incoming pulses by using a variable frequency generator and latch and reset the clock pulses.

CONCLUSION:

Experiment # 6

Objective: To construct time base for digital frequency counter for 1s, 10s, 100s, 1ms , 10ms, 100ms and 1sTHEORY:Many digital measuring techniques require an accurate time period or time base. The 1MHZ crystal controlled oscillator provides an extremely accurate output frequency (with a time period of 1us). The output frequency from final decade counter is exactly one-tenth of the input (toggling) frequency. This means the output time period is ten times the time period of input waveform. Thus the output time period from decade counter 1 is precisely 10us. Similarly the 6th decade counter is having a time period of exactly 1s.CIRCUIT DIAGRAM :

Pin configuration:1. Pin 1 to pin 7 and pins 9, 10and 11 are all the outputs of the IC.2. Pin 16 is for the positive supply and pin 8 is ground.3. Pin 15 is the reset point of the IC. A logic '0' to this pin (or by connecting it to the ground), gives a green signal to the IC, so that it can function. A logic '1' or a positive supply here will bring its proceedings to a stand still and will reset it. At this position pin 3 of the IC4017 stays at logic '1' where as all other outputs are logic 'lo'. 4. Pin 14 is the clock input of the IC 4017. An external clock signal to this point will make a logic '1' to proceed sequentially, beginning from pin 3 and ending at pin 11.5. Pin 13 is the clock enable point. A logic '1' to this pin will stop the IC 4017 from proceeding and its output will freeze at that instant at the particular output. Even if the clock signal at pin 14 is ON, the output cant shift as long as pin 13 is held at logic'1', therefore this point should be grounded. On the contrary if pin 14 is held at logic'1' and clock signal is applied at pin 1, every falling edge of the pulse will make the outputs to change state sequentially.6. Our main focus is on pin number 12 which gives output whose frequency is divided by 10.this is fed to input 14 of each decade counter.PROCEDURE:1. Connect 6 ICs 4017 in series such that output of each one from pin 12 is input clock of other at pin number 14.2. Connect 5 volts to pin 16 and ground rest of pins exept pin 14 (input) and pin (12).3. Give input from 1mhz crystal to first IC as clock.4. Time period of pulses of crystal is 1us.5. Every decade counter divides the frequency by 10 and multiplies time period by 10.6. So output of first decade counter is 10us.7. Similarly outputs of next decade counters are 100us,1ms,10ms,100ms and 1s8. By using jumpers output at various points can be taken to use a particular time base.9. This is shown in figure.

10. Check and compare input (crystal) time and time bases generated at decoder 3, 4,5 and on oscilloscope and calculate times to verify.

OBSERVATION : Write down the Time periods after decade counters 3,4,5 and 6.TRUTH TABLE: Time

Crystal Counter 3Counter 4Counter 5Counter 6

CONCLUSION:

Experiment # 7

Objective: Using the event counter (experiment#5), make the digital frequency counter with selectable time baseTHEORY:A convenient and accurate way of measuring frequency is to use a frequency counter. The frequency of a periodic waveform is defined as the number of cycles that occur per second. A frequency counter uses a precise internal time base and digital counters to produce a digital frequency readout.A frequency counter measures the frequency of the signal over a defined interval. To a frequency counter, the definition of frequency is f = where,n = number of cycles of the waveform countedTc = time interval over which the cycles are countedBLOCK DIAGRAM OF A FREQUENCY COUNTER:

Figure 7.1The above figure shows a block diagram of a basic frequency counter. The signal being measured is amplified and changed into a digital pulse train. This pulse train pulses through an electronic switch called the main gate and drives a series of digital counter. If the main gate is open, the value of digital counter increases by one for each new cycle of the signal being measured. If the main gate were to remain open, the digital counter would keep counting up indefinitely (or at least it ran out of digits). Instead the main gate is opened for a known length of time and the resulting number of cycles of the waveform is measured. This number represents the frequency of the waveform. To perform another measurement, the digital counter is reset and the main gate is once again reopened. The waveforms associated with this operation are shown in the figure given below:

Figure 7.2TASK:Measure the frequency of the signal with time base 1s, 10s, 100s,1ms, 100ms and 1s.

CONCLUSION:

Experiment # 8

Objective: To construct a resistive bridge circuit for receiving the proportional differential output voltage against a sensor (use ldr, pt-100, thermistors , thermocouple etc as sensor)THEORY:Making measurements with sensors is a common way in which many engineers and scientists encounter electrical devices. There are many different ways in which physical variables like temperature, light intensity and pressure can be measured electrically. Devices used to measure a physical variable are called sensors.UNDERSTANDING A BRIDGE CIRCUIT:The bridge circuit has twoarms(R1and R2constitute one arm here, and R3and RTconstitute the other arm). Each arm is composed of two resistors in series, and you may want to think of each arm as a voltage divider. The output is thedifferencebetween the outputs of the two voltage dividers. In the bridge circuit above we have also included some source resistance for the source which drives the bridge circuit.

Assuming negligible current flows through the voltmeter, the circuit paths abc and dfg can be assumed parallel and we can apply (1) to obtain

Now we can measure the voltage difference between nodes f and g to be

The bridge is balanced when Vfb = 0, i.e. voltage reading in meter M is zero. This occurs when RT / R3 = R2 / R1 .

LAB A

Using an RTD:

Procedure:

1) Construct the circuit as shown in the figure.

2) First adjust R2 which is a variable resistor to make the meter deflection to zero and find the resistance of RTD at room temperature by using the formula:

3) Now obtain the meter reading at different temperatures by heating the water with some heating mechanism.(Hint: You can measure the temperature with a thermometer.)

S No.Temperature in oCOutput Voltage (V)

4) Now obtain the Voltage vs Temperature curve it should be a straight line.

5) Now obtain a linear fit of temperature as a function of voltage, i.e. determine theslope m and intercept b such that:

T=mV+b

LAB BUSING A THERMISTOR:

PROCEDURE:

1) Construct the circuit as shown in the figure.

2) First adjust R2 which is a variable resistor to make the meter deflection to zero.

3) Obtain the meter reading at different temperatures by heating the water with some heating mechanism.(Hint: You can measure the temperature with a thermometer.)

S. No.Temperature in oCVoltage (V)

4) Now obtain the Voltage vs Temperature curve it should not be a straight line.

5) Obtain a polynomial fit of temperature as a function of voltage. A fourth-order polynomial given by : T = a V4 + b V3 + cV2 + d V + e

Note:Similarly perform the lab for other sensors such as LDR, Thermocouple etc.

Experiment # 9

Objective: Use LVDT in a bridge circuit to measure the displacement and display the proportional voltageAPPARATUS REQUIRED:

1. ITB-12-CE2. LVDT Set up3. Multimeter 4. Power chords

THEORY:

The linear variable differential transformer (LVDT) is a type of electrical transformer used for measuring linear displacement. The transformer has three solenoid coils placed end-to-end around a tube. The centre coil is the primary, and the two outer coils are the secondary. A cylindrical ferromagnetic core, attached to the object whose position is to be measured, slides along the axis of the tube. An alternating current is driven through the primary, causing a voltage to be induced in each secondary proportional to its mutual inductance with the primary. The frequency is usually in the range 1 to 10 kHz. As the core moves, these mutual inductances change, causing the voltages induced in the secondarys to change. The coils are connected in reverse series, so that the output voltage is the difference (hence "differential") between the two secondary voltages. When the core is in its central position, equidistant between the two secondary, equal but opposite voltages are induced in these two coils, so the output voltage is zero. When the core is displaced in one direction, the voltage in one coil increases as the other decreases, causing the output voltage to increase from zero to a maximum. This voltage is in phase with the primary voltage. When the core moves in the other direction, the output voltage also increases from zero to a maximum, but its phase is opposite to that of the primary. The magnitude of the output voltage is proportional to the distance moved by the core (up to its limit of travel), which is

why the device is described as "linear". The phase of the voltage indicates the direction of the displacement. Because the sliding core does not touch the inside of the tube, it can move without friction, making the LVDT a highly reliable device. The absence of anysliding or rotating contacts allows the LVDT to be completely sealed against the environment.

CIRCUIT DIAGRAM:PROCEDURE:

1. Install the LVDT position sensor and interface the 9 pin connector with ITB-12-CE.2. Switch on the kit.3. Connect the multimeter (or) CRO (in ac mv mode) across the T4 and T7 for thesecondary output voltage measurement.4. Adjust the micrometer in 10mm displacement and turns the zero displacement POT to 0 mm displacement on display.

5. Adjust the micrometer to 20mm displacement and turns the gain adjustment POT to 10mm on the display.6. Repeat the zero and span calibration until the core displacement is 0mm for 10mm displacement in micrometer and 10mm for 20mm displacement.7. After completion of the calibration, give the displacement in micrometer to core of the LVDT system.8. Gradually increase the micrometer displacement from 10mm to 20mm and note down the forward core displacement from 0mm to 10mm on the display and see the output voltage across T4 and T7.9. Similarly decrease the micrometer displacement from 10mm to 0mm and note down the reverse core displacement of 0 to 10mm on the display and see the output voltage across T4 and T7.10. Tabulate the readings of core displacement (mm), micrometer displacement and output voltage (mv).11. Plot the graph between core displacements (mm) along X-axis and see the output voltage (mv) across Y-axis.12. The same procedure repeated and note down the reverse core displacement of 0 to 10mm on the display and signal.13. Tabulate the readings of the core displacement, micrometer displacement and signal conditioned output voltage (V).14. Plot the graph between core displacement (mm) along X-axis and signal conditioned output voltage (V) along Y-axis.

OBSERVATIONS:

S. NO.MicrometerDisplacement(mm)

CoreDisplacement(mm)

SecondaryOutput Voltage(mv)

Signal ConditionedOutput Voltage(mv)

CALCULATIONS:

CONCLUSION:

Experiment # 10Objective: Using the bridge in experiment#8 measure/ display the output voltage with the help of a differential ADCTHEORY:The bridge circuit has twoarms(R1and R2constitute one arm here, and R3and RTconstitute the other arm). Each arm is composed of two resistors in series, and you may want to think of each arm as a voltage divider. The output is thedifferencebetween the outputs of the two voltage dividers. In the bridge circuit above we have also included some source resistance for the source which drives the bridge circuit.

Assuming negligible current flows through the voltmeter, the circuit paths abc and dfg can be assumed parallel and we can apply (1) to obtain

Now we can measure the voltage difference between nodes f and g to be

The bridge is balanced when Vfb = 0, i.e. voltage reading in meter M is zero. This occurs when RT / R3 = R2 / R1 .

TASK:Display the output of bridge circuit with the help of differential ADC.

Experiment # 11

Objective: To construct a digital volt meter using IC l7106/ IC l7107THEORY: The digital voltmeter is ideal to use for measuring the output voltage of your DC power supply. It includes a 3.5-digit LED display with a negative voltage indicator. It measures DC voltages from 0 to 199.9V with a resolution of 0.1V. The voltmeter is based on single ICL7107 chip and may be fitted on a small 3cm x 7cm printed circuit board. The circuit should be supplied with a 5V voltage supply and consumes only around 25mA. Brightness of the LED display segments can be varied by adding or removing 1N4148 small signal diodes that are connected in series. Use two 1N4148 diodes for higher LED display brightness.The use of 7805 5V voltage regulator is highly recommended to prevent the damage of ICL7107, 7660 ICs and to extend the operating voltages. 220 Ohm resistor should be connected to the PIN 4 on the first LED display. The voltmeter can also be configured to measure different voltage ranges and display higher voltage resolution. Replacing 1M with 100K resistor will allow to measure 0 - 19.99V voltages with 0.01V (10mV) accuracy.Use 10K potentiometer to set the reference voltage between PIN 35 and PIN 36 of the ICL7107 IC to 1V.

CIRCUIT DIAGRAM:

TASK:Construct a digital voltmeter for multiple ranges.

Experiment # 12

Objective: to understand and analyze signals on oscilloscope and spectrum analyzerEQUIPMENT REQUIRED:

Spectrum analyzer Oscilloscope Function generator Dual DC-power supply Theory:An oscilloscope is an electronic test instrument that displays electrical signals graphically, usually as a voltage (vertical or Y axis) versus time (horizontal or X axis) as shown in figure 1. The intensity or brightness of a waveform is sometimes considered the Z axis. There are some applications where other vertical axes such as current may be used, and other horizontal axes such as frequency or another voltage may be used. Oscilloscopes are also used to measure electrical signals in response to physical stimuli, such as sound, mechanical stress, pressure, light, or heat. For example, a television technician can use an oscilloscope to measure signals from a television circuit board while a medical researcher can use an oscilloscope to measure brain waves. Oscilloscopes are commonly used for measurement applications such as: observing the wave shape of a signal measuring the amplitude of a signal measuring the frequency of a signal measuring the time between two events observing whether the signal is direct current (DC) or alternating current (AC) observing noise on a signal Aspectrum analyzermeasures the magnitude of an input signal versus frequency within the full frequency range of the instrument. The primary use is to measure the power of the spectrum of known and unknown signals.

The input signal a spectrum analyzer measures iselectrical, however,spectralcompositions of other signals, such asacousticpressure waves andopticallight waves, can be considered through the use of an appropriatetransducer.Byanalyzingthespectraofelectricalsignals,dominantfrequency,power,distortion,harmonics,bandwidth, and other spectralcomponents of a signal can be observed that are not easily detectable intime domainwaveforms. These parameters are useful in the characterization of electronic devices, such aswireless transmitters.The display of a spectrum analyzer has frequency on the horizontal axis and the amplitude displayed on the vertical axis. To the casual observer, a spectrum analyzer looks like anoscilloscopeand, in fact, some lab instruments can function either as an oscilloscope or a spectrum analyzer.

SPECTRUM ANALYZER:

LINE SPECTRA OF PERIODIC SIGNALS:

1. Familiarize yourself with the controls of the spectrum analyzer [your instructor will give you a quick run on how to use the analyzer]. Use the following control settings: [Start freq: 0.0 Hz, Span: 6.25kHz].2. Use the oscilloscope to adjust the output of the function generator to 3V (p-p) sinusoid @ 500 Hz. Display this signal on the spectrum analyzer and record your results in table(1).3. Set the output of the function generator to 3V (p-p) square wave @ 500 Hz; display thesignal spectrum and record in Table (1).Repeat the step using a triangular wave instead of a square wave.

TIME (FREQUENCY) SCALING:

4. Set the symmetry - control of the function generator fully clockwise. Adjust the frequency dial of the generator to generate a single pulse [1 msec duration] repeated at a relatively slow rate ( 7.5 msec). Display this signal on the frequency analyzer. Plot the spectrum display on Graph (1).5. Adjust the frequency of the function generator to generate a single pulse of 0.5 msec duration repeated at a relatively slow rate. Display this signal on the frequency analyzer and plot the spectrum on Graph (1).

TASK:Compare the frequency spectrum of the 1 msec-pulse with that of the 0.5 msec-pulses; both are of equal amplitude.

OSCILLOSCOPE:a. Reset the oscilloscope back to a known starting point and use the front- panel controls to create this display. Normally, for greatest accuracy, the waveform is adjusted vertically to fill as much of the display as possible

TASK # 01:Determine the amplitude of the signal by counting the number of vertical divisions and multiplying that by the vertical scale factor. Write the amplitude here:

TASK # 02:Calculate the period of the signal by counting the number of horizontal divisions and multiplying that by the horizontal scale factor. Write signal period here:

TASK # 03:Calculate the frequency of the signal by performing the following calculation: Frequency = 1/(signal period).

CONCLUSION:

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