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Lab#2: Electrical Instruments
MECH 380
Mechanical Engineering Measurements
Laboratory Section MECH 380-154
Prepared for
Dr. Fanben Meng and Teaching Assistant Team
Department of Mechanical and Materials Engineering
University of Nebraska-Lincoln
by
Cody Hora
(signature)
Date: September 19, 2024
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Contents
1 Abstract
3
2 Experimental Description
3
3 Results and Discussion
8
4 Conclusion
14
5 Appendix
16
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Abstract
In this lab, a variety of electrical instruments were used to collect a variety of data. Among
the instruments used were an analog multimeter, two digital multimeters, a clamp meter, a
DC power supply, a function generator, an electronic counter, and a digital oscilloscope.These
instruments were used to collect different types of data such as voltage and current for both
DC and AC electrical signals as well as resistance and power. The first station involved voltage
measurements using the three types of multimeters available for comparison between accuracy.
The period and voltage produced by the function generator were recorded using the oscilloscope
and the frequency using the electronic counter. A resistor was then selected and measured using
the three types of multimeters to find resistance. A transient for an oscillating signal was found
using triggering on the oscilloscope. Next, AC current and power were recorded for a hair
dryer using the clamp meter. All results were within expected ranges with no significant errors
or obstacles in data acquisition. Voltage, frequency, resistance, and current measurements
all agreed with the settings of the power sources/signals. The biggest challenge this lab was
properly interpreting data outputs from the digital multimeter due to inexperience and nonintuitive interface design.
2
Experimental Description
To begin the lab, an analog multimeter and two digital multimeters were gathered (see
figures 1 through 3). Then, the DC power supply (see figure 7) was set to output 5.0VDC . The
digital oscilloscope (see figure 9)was used to record the DC voltage by using DC coupling, setting
the vertical to be 2.00 V/Div and the horizontal to be 10ms/div and setting the ground to zero.
The three multimeters were also used to record the voltage by connecting the appropriate probes
from the DC source to the multimeters. This setup is shown in figure 4 where the multimeter
can be replaced by any of those in figures 1 through 3.
Next, the function generator (see figure 8) was set to output a 500 Hz, 2.0 V amplitude
sine wave. The oscillosope was then connected to the function generator to read and record
the period and Vp k − pk. The signal counter (see figure 10) was also used to record the signal
frequency and period. Finally, the three multimeters were set to read and record AC voltage.
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Figure 1:
Triplett 630- Figure 2: Fluke 115 Digital
APLK Analog Multimeter
Multimeter
Figure 3: Hewlett Packard
34401A Digital Multimeter
Figure 4: Setup for Oscilloscope and Multimeter DC Voltage Reading
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The setup for this, a square wave, and a 20kHz sine wave is shown in figures 5 and 6.
Figure 5: Setup for AC Voltage Reading
Figure 6: Setup for Electronic Counter
readings
Following the sinewave, a square wave was generated using the function generator with the
same frequency and voltage settings. This time, only the voltages were recorded using the
three multimeters and oscilloscope. Finally, the settings on the function generator were reset
to output a 20.0 kHz, 2.0 V amplitude sine wave. Again, only the voltages were recorded using
the three multimeters and oscilloscope.
Figure 7: BK Precision 1672 DC Power Figure 8: Agilent 33120A Function GenerSupply
ator
Figure 9: Tektronix TDS 1002B Digital
Oscilloscope
Figure 10: Hewlett Packard 5315A Electronic Counter
The focus of the lab was then shifted to interpret standard resistor bands as per figure 11
and record the resistance. The resistor selected, following the order of bands A-D in figure 11,
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Figure 11: Carbon Composition Resistor Color Code
was brown-black-brown-silver. The nominal resistance was recorded based on the color code
and then the three multimeters were used to record the resistance. This setup is shown in figure
12.
Figure 12: Setup for Resistance Measurement
The next procedure involved using a clamp meter (see figure 13) and a Conair Ionshine 1875
hair dryer (see figure 14) to measure current. The clamp meter was set to measure AC within
a 20 A range. Clamping the meter around only one of the wires (the cord of the dryer has two
different wires which, when measured together, cancel out due to opposite current directions,
refer to figure 15), current measurements for the three speed settings (off, low, high) and two
heat settings (cool, warm, hot) were recorded using the clamp meter (see appendix for in-lab
data). The voltage threshold used by the dryer according to the manufacturer was 125 V, but
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110 V is used for power calculations using P = V · I.
Figure 13: Extech Instruments AC/DC
Digital Clamp Meter
Figure 14: Conair Ionshine 1875W
Figure 15: Setup for Dryer Current Measurement
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Results and Discussion
1. Derive a numerical value for the ratio of the rms voltage to the peak-to-peak voltage a) for
a sinewave and b) for a square wave. Use these conversion factors to fill out your data
sheet. Compare the calculated oscilloscope AC voltages with the corresponding multimeter
AC voltage readings. For sinewave input, how do the multimeter AC voltage readings
compare at 500 Hz? at 20.0 kHz?
For a sinewave, the voltage can be expressed as:
v(t) = Vo sin(ωt)
where Vo is the peak voltage. The RMS (root mean square) voltage is defined as:
s
Vrms =
1
T
Z T
[v(t)]2 dt
0
For a complete cycle of the sinewave:
s
Vrms =
1
T
Z T
Vo2 sin2 (ωt)dt
0
We know that:
Z T
sin2 (ωt)dt =
0
T
2
Thus, the RMS voltage is:
1
Vrms = Vo × √
2
The peak-to-peak voltage is simply:
Vpp = 2Vo
Hence, the ratio of the RMS voltage to the peak-to-peak voltage for a sinewave is:
1
Vo × √2
Vrms
1
=
= √ ≈ 0.3536
Vpp
2Vo
2 2
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For a square wave, the voltage alternates between +Vo and −Vo . The RMS voltage is
defined similarly:
s
Vrms =
1
T
Z T
[v(t)]2 dt
0
For a square wave, v(t) = ±Vo , so:
s
Vrms =
1
T
Z T
Vo2 dt = Vo
0
The peak-to-peak voltage is the same as for the sinewave:
Vpp = 2Vo
Thus, the ratio of the RMS voltage to the peak-to-peak voltage for a square wave is:
Vrms
Vo
1
=
= = 0.5
Vpp
2Vo
2
Therefore:
1
≈ 0.3536.
• For a sinewave, the ratio VVrms
= 2√
pp
2
• For a square wave, the ratio VVrms
= 0.5.
pp
Note that for both ratios, multiplying by two generates the ratio between the amplitude
of the wave to the rms voltage.
Hence, for a sine wave:
Vo
Vrms = √
2
For a square wave the RMS voltage is the same as the voltage amplitude.
Using the Vpp from table 7 and the ratio between Vpp and Vrms for a sine wave, Vrms =
1.47Vrms for the oscilloscope. This value is used to compare the different instruments
used for AC voltage measurement in table 1. The small percent errors indicate accuracy
of the instruments/measurements with the calculated value from the oscilloscope.
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Instrument
Triplett
Fluke
Hewlett Packard
Measured Voltage (Vrms )
1.425
1.415
1.4154
% Error w/ Oscilloscope
3.06 %
3.71%
3.71%
Table 1: Measured RMS Voltage Compared to Calculated Oscilloscope RMS Voltage (2.00 V,
500Hz Sine Wave)
Applying the same process to the square wave data yields the following relationships
where the measured square wave Vpp = 4.24V and the calculated rms voltage is 2.12 V
using the 0.5 ratio between peak-to-peak and rms voltage for square waves. As evinced
Instrument
Triplett
Fluke
Hewlett Packard
Measured Voltage (Vrms )
2.225
1.977
2.009
% Error w/ Oscilloscope
4.95%
6.75%
5.24%
Table 2: Measured RMS Voltage Compared to Calculated Oscilloscope RMS Voltage (2.00 V,
500Hz Square Wave)
by the percent errors, the analog multimeter was actually closest to the calculated rms
voltage from the oscilloscope but all values have relatively small percent errors and thus
show relative accuracy of the instrumental measurements.
Finally, when a 2.00 V, 20 kHz sine wave was generated using the function generator,
the oscilloscope read 4.04 Vpp . Using the sine wave conversion factor, the calculated rms
voltage is 1.43Vrms . The measured values using the multimeters are compared with this
calculated value in table 3. As can be seen, the Fluke multimeter had a significant percent
Instrument
Triplett
Fluke
Hewlett Packard
Measured Voltage (Vrms )
1.425
0.490
1.4156
% Error w/ Oscilloscope
0.35%
65.73%
1.01%
Table 3: Measured RMS Voltage Compared to Calculated Oscilloscope RMS Voltage (2.00 V,
20kHz Sine Wave)
error with the calculated oscilloscope value, especially when compared to the error in table
1. This can likely be attributed to the Fluke multimeter not being calibrated/designed
for such a high frequency resulting in the measurement error. The other two multimeter
readings were, however, extremely close to their 500Hz counterparts in table 1 (the Triplett
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readings were identical and the percent difference between the Hewlett Packard readings
is merely 0.01%).
2. Inexpensive analog multimeters determine the AC voltage by measuring the DC voltage
of the rectified input signal and then compensating with a correction factor. Most often a
sinewave input is assumed. If the waveform is not a sinewave an error in the indicated
AC voltage results.
a. Derive a numerical value for the ratio of the rms (AC) voltage for a sinewave to the
DC voltage of the same sinewave after passing through a full wave rectifier (i.e., this
is the same as taking the absolute value of the sinewave).
The rectified DC voltage for a sine wave is known as VDC = 2Vπo by the following:
VDC =
VDC =
VDC =
1
π
1
T
Z T
V (t)dt
0
Z π
Vo · sin tdt
0
Vo
2Vo
[− cos π + cos 0] =
π
π
Using the relationship of Vo to Vpeak :
√
Vo
√
π 2
Vrms
2
= Vo =
VDC
4
2π
(2)
b. Derive a numerical value for the ratio of the rms (AC) voltage for a square wave to
the DC voltage of the same square wave after passing through a full wave rectifier
(i.e., this is the same as taking the absolute value of the square wave).
The rectified DC voltage for a square wave is:
VDC =
1
T
Z T
1
VDC =
T
VDC =
V (t)dt
0
Z T
Vo dt
0
Vo
· T = Vo
T
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Using the relationship of Vo to Vpeak :
Vrms
Vo
=
=1
VDC
Vo
(4)
c. If the AC voltage of a square wave is read using an inexpensive analog multimeter
calibrated for sinewave input only, what would be the expected percent error? What
can you conclude (if anything) about the analog multimeter used in LAB #2?
The percent error is found by comparing the DC rectification conversion factor for
sine with that of square waves. The analog multimeter essentially measures the
rectified voltage and thus approximates AC signals by taking 2Vπo (the DC voltage
rectification for the sine wave). However, it was concluded that true DC rectification
for a square wave is simply Vo as per part 2b. Thus, the percent error is found by
the following, using the ratios between RMS voltage and DC rectification:
Percent Error =
VDC,true − VDC,measured
· 100%
VDC,true
√
Vo − 2π4 2 Vo
Percent Error =
· 100%
Vo
Percent Error = |1 − 1.1107| · 100%
Percent Error = 11.07%
Based on this expected percent error, one would expect the same error to occur in the
experimental data as in table 2 and thus the analog multimeter data to be unreliable
for a square wave. Yet, the data shows a similar percent error for the square wave
as with the sine wave. This indicates that, with reasonable confidence, the Triplett
analog multimeter used in this lab was well calibrated to measure both square and
sine waves.
3. Fill out your data sheet with the calculated oscilloscope and counter periods and frequencies
where indicated.
See appendix for completed data sheet and/or refer to table 7.
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4. Were your resistance readings within the stated resistor tolerance range?
First, the nominal resistance is calculated using the colored bands and the equation indicated in figure 11:
R = AB. · 10C ± D = 10. · 101 ± 10%
R = 100 ± 10%Ω
Thus, using the tolerance, the range of resistance values is simply [90Ω, 110Ω]. The
following table indicates the deviation from the nominal value and the measured value for
resistance using the three types of multimeter.
Instrument
Triplett
Fluke
Hewlett Packard
Measured Resistance (Ω)
95
98.5
98.298
% Error w/ Nominal
5.0 %
1.5%
1.7%
Table 4: Measured Resistances Compared to Nominal
As evidenced by the percent errors in table 4, all the measured resistances fall within the
nominal tolerance of the resistor.
5. The inputted electrical power to the hair dryer is used to drive the fan motor and the
heating coil. How does your measured maximum power compare with the advertised value?
Using your tabled data, discuss the relationship between speed setting, heat setting, and
measured power, and reason whether the comparison between your measured maximum
power and the advertised value is consistent with the results.
Fan Speed
Off
low
low
low
high
high
high
Heat Setting
cool
warm
hot
cool
warm
hot
Current (A)
0.01
0.91
4.15
6.16
1.48
7.61
13.42
Power (W)
1.10
100.1
456.5
677.6
162.8
837.1
1476.2
Table 5: Fan Settings with Current and Power Readings
Observing the data in table 5, there is a clear relationship between observed power and
fan speed and heat setting. The general relationship is that as either/both fan speed and
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heat setting increase, so too does the power consumption. For instance, keeping a cool
heat setting and changing the fan speed to high saw a 62.6% increase. Similarly, a high
fan speed and changing from cool to hot increased the power by 806.8%. The increases
based purely on heat setting indicate that this setting influences power consumption more
than fan speed.
The maximum measured power (which occurred at a high fan speed with hot heat setting)
was 1476.2 W which, when compared to the advertised power setting of 1875 W, is 21.3%
less wattage than advertised. It can be concluded that the maximum power consumed
is consistent with the manufacturers advertised value because of the only 21.3% increase
and the fact that the room wasn’t particularly cold. It can be reasoned that if the room
was cooler, the dryer would need to work harder (use more power) to output the same
heat setting at a high speed and that the advertised value is more of a threshold than
the precise power consumption. Additionally, there is likely a funnel system to optimize
the air flow which will help reduce the current draw to achieve the same results, hence
why the experimental value is lower than the advertised. Finally, the factor of safety
compared from the experimental power draw to the advertised is 1.25 which was likely a
design choice to avoid overheating and/or user injury.
4
Conclusion
In this lab, a range of electrical instruments was utilized to measure various parameters,
including voltage, current, resistance, and power for both DC and AC signals. These measurements were carried out using an analog multimeter, two digital multimeters, a clamp meter, a
DC power supply, a function generator, an electronic counter, and a digital oscilloscope. The
results obtained from these instruments were consistent with the expected values and showed
no significant deviations apart from the Fluke multimeter which had significant error with the
expected for a 20kHz sine wave.
Voltage measurements using the three multimeters demonstrated comparable accuracy,
while the oscilloscope and electronic counter provided reliable readings for period, voltage,
and frequency generated by the function generator. Resistance measurements using the three
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multimeters agreed with expected values, and the transient response of an oscillating signal
was successfully captured using the oscilloscope’s triggering function. Additionally, the clamp
meter was used effectively to measure AC current and power for a hair dryer.
Overall, the experiment was successful, with minimal challenges encountered during data
collection. However, interpreting data from the digital multimeters posed a slight challenge
due to unfamiliarity with the devices and their user interfaces. Despite this, the lab effectively
demonstrated the functionality and accuracy of the instruments used in measuring key electrical
parameters.
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Appendix
Instrument
Oscilloscope
Triplett
Fluke
Hewlett Packard
Measured DC Voltage (V)
5.00
5.1
5.029
5.0332
% Error w/ Supply (5.0 V)
0.0%
2%
0.58%
0.66%
Table 6: Measured DC Voltages Compared to Supply
Value
Function Generator Frequency
Oscilloscope Period
Oscilloscope Frequency (Calculated)
Counter Frequency
Counter Period
Counter Frequency (Calculated
Counter Period (Calculated)
Vo (Function Generator)
Vpp (Oscilloscope)
Recorded Quantity
500 Hz
2.000 ms
500 Hz
500.0 Hz
2.000 ms
500.0 Hz
2.000 ms
2.00 V
4.16 V
Table 7: Recorded and Calculated Quantities for Sine Wave (2.00 V & 500Hz)
University of Nebraska - Lincoln Department of Mechanical and Materials Engineering
MECH 380 MECHANICAL ENGINEERING MEASUREMENTS
LABORATORY #2
Electrical Instruments
OBJECTIVE:
Familiarize with the use of common laboratory electrical instruments. These
instruments include an analog multimeter, two digital multimeters, a clamp meter,
a DC power supply, a function generator, an electronic counter, a digital
oscilloscope, and a computer-based data acquisition and control system.
EQUIPMENT:
Triplett 630-APLK Analog Multimeter
Fluke 115 Digital Multimeter
Extech Instruments AC/DC Digital Clamp Meter
Hewlett Packard 34401A Digital Multimeter
BK Precision 1672 DC Power Supply
Agilent 33120A Function Generator
Hewlett Packard 5315A Electronic Counter
Tektronix TDS 1002B Digital Oscilloscope
Dell MiniTower PC
National Instruments PCIe-6341 Data Acquisition Board
National Instruments BNC-2110 Interface
LabVIEW software
NOTE: Be careful not to short out or ground the high side output of the power supply or function
generator. When using the dual prong banana plug jack, be sure to maintain proper polarity. The
"ground" or "common" side has a raised ridge.
PROCEDURE
1. Voltage Measurement and Oscilloscope Display
a) Connect the output of the DC power supply (+/-) to CH1 (channel 1) of the digital oscilloscope.
Use the DC power supply to create a 5.0 V (as indicated by the power supply front panel) DC
voltage signal. Display the DC voltage on the oscilloscope. (Note: You might want to use the
following settings to get started. Coupling => DC, Volts/Div => Coarse, Probe Voltage => X1,
Invert => Off, Vertical => 2.00 V/Div, Horizontal => 10 ms/Div, Trigger Mode => Auto.) Read
and record the DC voltage as indicated by the oscilloscope display (you can use Coupling =>
Ground to zero your trace), and as indicated by each of the three types of multimeters.
b) Use the function generator to create a 500 Hz frequency, 2.0 V amplitude (as indicated on the
front face of the function generator)* sinewave and display on the oscilloscope. Read and record
the signal period and peak-to-peak voltage as shown on the oscilloscope screen. Read and record
the signal frequency and period as indicated by the electronic counter. Read and record the AC
voltage using each of the three multimeters.
*Note: “Vpp” on the function generator does not stand for “peak-to-peak”. Setting a 2.0V
amplitude results in 4.0V peak-to-peak.
c) Repeat part b) using a square wave instead of a sinewave. Perform voltage measurements only.
d) Repeat part b) using a 20.0 kHz (instead of 500 Hz) sinewave. Perform voltage measurements
only.
2. Resistance Measurement
Record the reference number of your resistor. Sketch the resistor showing the placement and
color of the bands. Interpret and record the indicated resistor nominal value and tolerance (refer
to the attached resistor color code sheet). Read and record the resistance of the resistor using each
of the three multimeters.
3. Digital Oscilloscope Triggering
a) Connect the output of the function generator to CH1 (channel 1) of the oscilloscope. Using the
function generator and benchtop digital multimeter, create and display a 1000 Hz, 1.0 Vrms
triangular wave on the oscilloscope. Now press TRIG MENU on the oscilloscope and change the
(sweep) MODE from AUTO to NORM and adjust the TRIGGER LEVEL so that the trace
triggers with a positive slope at a location about two-thirds up a positive peak of the triangular
waveform. (Note the trigger time is indicated by the downward arrow at the top of the oscilloscope
screen and the trigger level is indicated by the leftward arrow on the right side of the oscilloscope
screen.) Have your laboratory teaching assistant (TA) verify your arrangement by initialing your
data sheet.
b) Now disconnect the input to the oscilloscope and press SINGLE SEQ (single sweep).
c) Now reconnect the signal lead to the oscilloscope to create a transient. The resultant trace should
show a "pretrigger delay" across the left half of the oscilloscope screen. (Repeat several times
until you obtain a particularly interesting looking transient.) Have your laboratory teaching
assistant (TA) verify your arrangement by initialing your data sheet. Make a sketch of your
oscilloscope display on your datasheet.
4. AC Current Measurement Using a Clamp Meter
Open and close the ExTech Clamp Meter around one side (the side without the electrical tape) of
the hair dryer power cord. Set the Clamp Meter to AC with a 20 Amp range. Measure and record
the AC current of the hair dryer at each of the six speed and heat setting combinations. Multiply
each of the current readings by 110 (volts) to obtain the power consumption in watts. Record the
calculated power on your data sheet.
5. Getting Started: LabVIEW (continued from Lab #1)
a) Use the provided links to watch the listed LabVIEW introductory videos:
Debugging and Handling Errors
“Using Debugging Tools in NI LabVIEW”
https://www.youtube.com/watch?v=1Rx6AXhF31I
Signal Processing
“Make Decisions Faster with Inline Analysis…”
NEED TO FIND REPLACEMENT VIDEO
Acquiring and Generating Data
“Taking a Measurement with Your Computer”
https://www.youtube.com/watch?v=ofzbA3keOYE&t=27s
6. Computer-Based Data Acquisition Demonstration
Follow the instructions on the attached LabVIEW Demonstration #1 handout. Have your
laboratory teaching assistant (TA) initial your handout to verify the completion of the
demonstration.
LABORATORY ANALYSIS
on
phone
=>
I
1. Derive a numerical value for the ratio of the rms voltage to the peak-to-peak voltage a) for a
sinewave and b) for a square wave. Use these conversion factors to fill out your data sheet.
sand
Compare the calculated oscilloscope AC voltages with the corresponding multimeter AC voltage
readings. For sinewave input, how do the multimeter AC voltage readings compare at 500 Hz?
at 20.0 kHz?
2. Inexpensive analog multimeters determine the AC voltage by measuring the DC voltage of the
rectified input signal and then compensating with a correction factor. Most often a sinewave input
is assumed. If the waveform is not a sinewave an error in the indicated AC voltage results.
a) Derive a numerical value for the ratio of the rms (AC) voltage for a sinewave to the DC voltage
of the same sinewave after passing through a full wave rectifier (i.e., this is the same as taking the
absolute value of the sinewave).
b) Derive a numerical value for the ratio of the rms (AC) voltage for a square wave to the DC voltage
of the same square wave after passing through a full wave rectifier (i.e., this is the same as taking
the absolute value of the square wave).
c) If the AC voltage of a square wave is read using an inexpensive analog multimeter calibrated for
sinewave input only, what would be the expected percent error? What can you conclude (if
anything) about the analog multimeter used in LAB #2?
3. Fill out your data sheet with the calculated oscilloscope and counter periods and frequencies
where indicated.
4. Were your resistance readings within the stated resistor tolerance range?
5. The inputted electrical power to the hair dryer is used to drive the fan motor and the heating coil.
How does your measured maximum power compare with the advertised value? Using your tabled
data, discuss the relationship between speed setting, heat setting, and measured power, and reason
whether the comparison between your measured maximum power and the advertised value is
consistent with the results.
Vo/f
= .
·
m
mid- to
denfe pr
·a
Vo
Von
=d
=
Z
LabVIEW Demonstration #1: Analog Input
a) Connect the output of the function generator to both the digital oscilloscope (CH 1) and to analog
input channel 0 (AI0, set to FS) of the DAQ board. Adjust the function generator to create a 40.0
Hz, 200 mV amplitude, sinewave and appropriately adjust the oscilloscope to display the
sinewave on the oscilloscope screen.
b) On the Desktop, start LabVIEW by double-clicking on the “NI LabVIEW 2013” icon.
c) Open a new VI (Virtual Instrument) by selecting “Blank VI” under “Create Project”.
d) Put the resulting “Front Panel” and “Block Diagram” side-by-side with the Front Panel on the left
and the Block Diagram on the right.
e) To add a digital input device, right click on the Block Diagram and select Express => Input =>
DAQ Assist and place the DAQ Assistant icon on your Block Diagram. An input screen will
appear. Under “Acquire Signals” select Analog Input => Voltage => ai0 (this is channel 0 on the
NI PCIe-6341 data acquisition and control board that is plugged into an expansion slot of your
PC). Click “Finish” and a DAQ Assistant Dialog Box will appear. In the Dialog Box, set the
“Signal Input Range” to Max = 2 (Volts) and Min = -2 (Volts), set the “Samples to Read” = 1000,
and set the “Rate (Hz)” to 10,000. Now click “OK” to accept and close the Dialog Box. (You
can always return to the Dialog Box by double-clicking on the DAQ Assistant icon.
f) Next, right click on the Front Panel and add a “Waveform Graph” by selecting Graph =>
Waveform Graph and placing the Waveform Graph on the Front Panel.
g) Now on the Block Diagram, connect a wire from the “data” output of the DAQ Assistant to the
input of the “Waveform Graph”.
h) Next “Run” your VI (either use Operate => Run or just click the Run icon on the Ribbon). You
should see the inputted sinewave on your display. If not, go through the instructions again, or
have your TA help you. Each time you click Run, a new digital sample record will be obtained
and displayed.
i) Now, on the Front Panel, right-click on the Waveform Graph and under Properties => Scales,
uncheck Autoscale on both the Time(X) Axis and Amplitude(Y) Axis and set the Min/Max of the
Time Axis to 0.0/0.1 and set the Min/Max of the Amplitude Axis to -0.4/+0.4. Click “OK” to
accept your property changes and return to the Front Panel. Next left-click on the Waveform
Graph and appropriately adjust the size of your Graph.
j) Next “Run” your VI. You should once again see the inputted sinewave on your display. Use the
function generator to slightly vary the frequency and/or slightly vary the amplitude and/or change
the wave type (sinewave, triangular wave, square wave, sawtooth wave) of your input and verify
with the corresponding VI output (use “Run Continuously” if you want, but be sure to stop when
done).
k) When operating properly, show your TA and then have your TA initial below verifying your
successful completion of the LabVIEW VI.
Al
First part of LabVIEW DEMO #1 successfully completed ________
l) Now readjust your function generator to output the original 200 mV amplitude, 40 Hz sinewave.
m) On the Block Diagram, click (once) on the DAQ Assistant icon and resize to more easily view
the input/output arrows for the icon. Right-click on the “number of samples” input arrow and use
Create => Control to create a control (on the Front Panel) for setting the number of samples.
Likewise, right-click on the “rate” input arrow and create a control for setting the sample rate.
Note: At this point you might want to use Edit => Clean up diagram to give your Block Diagram
a better look.
n) Now “Run” your VI. You should once again see the inputted sinewave on your display. Keeping
the sample rate at 10000 S/sec, vary the number of samples thru the values 100, 200, 500, 1000,
and 2000 and interpret what is shown on the corresponding waveform display. Next try setting
the number of samples equal to the sample rate thru values of 100, 200, 500, and 1000 and
interpret what is shown on the corresponding waveform display. Try other combinations of
number of samples and sample rate if you want.
o) When operating properly, show your TA and then have your TA initial below verifying your
successful completion of the LabVIEW VI.
Al
Second part of LabVIEW DEMO#1 successfully completed ________
p) Now close LabVIEW (“Don’t Save”) and return to the Desktop.
Reference: S. Wolf, Guide to Electronic Measurements and Laboratory Practice, Prentice-Hall,
Englewood Cliffs, New Jersey, 1973.
MECH 380 MECHANICAL ENGINEERING MEASUREMENTS
LABORATORY #2
DATA SHEET
NAME:___________________________________
Cody Hora
151
LAB SECTION:____________________________
z0z4
Sept 19
DATE:___________________________________
,
1. Voltage Measurement and Digital Oscilloscope Display
a) DC VOLTAGE
DC power supply:________5.0 V___________
00 1
2 S
2 00
Oscilloscope:________div
× ________
V/div = _________________________
5
.
.
.
S 1
V
Triplett multimeter:____________________
.
5 029 V
Fluke multimeter:_______________________
.
5 0332 V
HP multimeter:__________________________
.
b) SINEWAVE AC VOLTAGE, FREQUENCY (f), AND PERIOD (T)
Function generator frequency:________500 Hz_______
2
1.00 M s/div = __________________
2000
Oscilloscope period:________div
× ________
.
000
ms
500 Hz
**A 3. Oscilloscope calculated frequency: 1/T = _____________________
.
002
500
0
Hz
Counter frequency:________________________________
.
000
2
Counter period:___________________________________
ms
,
Soo
**A 3. Counter calculated frequency: 1/T = ________________________
He
**A 3. Counter calculated period: 1/f = ___________________________
2
.
000
ms
Function generator indicated voltage amplitude:_______2.00 V_______
4 16 v
Oscilloscope peak-to-peak voltage:____________________________
.
Note: **A => Designated values are to be filled in later as part of the Laboratory Analysis.
**A 1. Oscilloscope calculated AC voltage:
Vrms
=
1 44 ?
.
1.
4 16
Vrms
E Vrms/Vp-p =______________________
________
Vp-p × ________
47
.
1
425
Vrms
Triplett multimeter voltage:________________________________
.
1
415
Vrus
Fluke multimeter voltage:___________________________________
1
.
4194
Vrms
HP multimeter voltage:______________________________________
.
c) SQUARE WAVE AC VOLTAGE
Function generator indicated voltage amplitude:_______2.00 V_______
4
24
Oscilloscope peak-to-peak voltage: ______________________
Upp
.
Vrms
:
z
.
**A 1. Oscilloscope calculated AC voltage:
2
4 24
Vrms
S
_________V
Vrms/Vp-p =______________________
p-p × ________
on
o
.
.
12
.
225
Triplett multimeter voltage:________________________________
Uras
2
.
977
Vrms
1
Fluke multimeter voltage:___________________________________
.
Vrms
HP multimeter voltage:______________________________________
2
.
009
d) SINEWAVE AC VOLTAGE AT 20.0 kHz
Function generator indicated voltage amplitude:_______2.00 V_______
4 32
Oscilloscope peak-to-peak voltage:___________________________
Vo-p
.
Vms
:
1 43 V
.
**A 1. Oscilloscope calculated AC voltage:
1 43 V
Ye
7 04 p-p × ________
________V
Vrms/Vp-p =______________________
.
2
.
.
1 425 Vrms
Triplett multimeter voltage:________________________________
.
0 490 Vrms
Fluke multimeter voltage:___________________________________
.
1 4156 Vums
HP multimeter voltage:______________________________________
.
2. Resistance Measurement
I
Resistor reference number:________________________
Sketch of the resistor:
↑ ,
brown
Brown
Blas
Brown
Silver
sile a
·
Eblade
100
110 %M
Resistance and tolerance:_____________________________________________
10)
as
re
Triplett multimeter resistance:_______________________________________
(9 8
.
.
98 6 M
Fluke multimeter resistance:__________________________________________
.
98 2987
HP multimeter resistance:_____________________________________________
.
3. Digital Oscilloscope Triggering
a) 1000 Hz, 1 Vrms, triangular wave with left-hand-side trigger point just before a positive peak
Al
Al
TA's Approval __________________________
b) Pretriggered delay trace of cable reconnect transient
TA's Approval __________________________
c) Sketch of transient waveform:
4. AC Current Measurement Using a Clamp Meter
1875
Conair
lonshine
Hair dryer make and model:_________________________________________
1875
Hair dryer specified maximum power (from box):_______________
watts
Fan Speed
Heat Setting
Electrical Current (A)
Off
xxx
0
Low
Cool
0
Low
Warm
U
Low
01
.
W=
V
1
.
10
100 .
15
156
Hot
6 16
677
High
Cool
1
45
162
High
Warm
High
Hot
.
.
.
7
13
.
.
1
:
V=
Electrical Power (W)
91
.
.
S
.
6
.
S
.
41
837 .
47
1476
·
I
lov