Download A) Resistance, Voltage and Current Measurement using Analog

Laboratory Module
LAB 1: INTRODUCTION TO INSTRUMENTATION AND MEASUREMENTS
DNT 121
Instrumentation & Measurement
Semester 2 (2006/2007)
LECTURER:
PLV:
TECHNICIAN:
MR ZULKARNAY ZAKARIA
MRS FARIDAH HASSAN
MR BAZLI BAHADON
Student’s Particular
NAME:
MATRIX NO:
DATE:
SIGNATURE:
School of Mechatronic Engineering
Kolej Universiti Kejuruteraan Utara Malaysia
SEM 2:06/07
DNT 121 Instrumentation & Measurement
Lab 1: Introduction to Instrumentation & Measurements
PART A: Introduction to Electrical Instrument & Measurements
1.0
OBJECTIVES
1.1
1.2
To learn the operation of analog multimeter.
To understand the measurement techniques of resistance, voltage and current values.
2.0
PARTS AND EQUIPMENT



Breadboard and wires.
DC power supply
Multimeter
3.0
PROCEDURE
3.1
Resistance Measurement



500 Ω resistor
2.2 kΩ resistor
470 kΩ resistor
Follow step-by-step procedure below to measure the value of each resistor.
a) Turn your "Selector Knob" to X1K Resistance Measurement Range.
b) Touch your RED PROBE and BLACK PROBE together. You will see your meter needle turn
from ∞ to 0 Ω. Adjust your calibration knob until your meter needle precisely on 0Ω.
c) Drag your RED PROBE to the first lead of resistor and the BLACK PROBE to the
second
lead. See figure 1 for details.
d)
e) Figure 1
f) Read the value of the resistor using the respective selected range at Selector Knob.
g) If you select X1K at selector knob, the value from reading scale must be multiply by 1000.
h) Record your measurements in Table 1.
2
SEM 2:06/07
3.2
DNT 121 Instrumentation & Measurement
Lab 1: Introduction to Instrumentation & Measurements
DC Voltage Mesurement
a) Using the measure resistor in procedure 3.1, Construct the following circuit on the breadboard.
b) Set the DC power supply to 5V (Vs).
Figure 2
c) By using the Analog multimeter measure the Voltage drop on each resistor. Follow step by step
procedure below:
 Turn your "Selector Knob" to the suitable DC Voltage Measurement Range.
 Drag your RED PROBE to the one of resistor lead and the BLACK PROBE to the other lead.
 Read the value of the voltage using selected range at Selector Knob.
d) Record your measurement in Table 2.
3.3 DC Current Measurement
a) Using the same circuit in procedure 2 measure the current across each resistor. Follow step by
step procedure below:
 Turn your "Selector Knob" to the suitable DC Current Measurement Range.
 Brake the circuit at point where current need to be measured.
 Drag your RED PROBE to the first point and the BLACK PROBE to the second point.
 Read the value of the current using selected range at Selector Knob.
b) Record your measurement in Table 2.
3
SEM 2:06/07
DNT 121 Instrumentation & Measurement
Lab 1: Introduction to Instrumentation & Measurements
PART B: Error Measurement
4.0
OBJECTIVES
4.1
4.2
4.3
To learn on type of measurement error
To learn on method/technique of measurement process
To investigate sources of error in measurement and to apply the equations provided to
analyze the error.
5.0
PARTS AND EQUIPMENT





1 multimeter
6 composition resistors, 2.2kΩ
1 resistor, 1kΩ
1 DC power supply
Breadboard
6.0
THEORY
6.1
Measurement Process
Measurement process is a process which generates information for measurement, e.g. electric
circuits, furnace, human heart and weather system.
6.2




6.3



6.4

Before measurement:
Procedure of measurement ~Identify the parameter / variable to be measured and how to
record the result.
Characteristic of parameter ~ Should know the parameter that is to be measured: ac, dc,
volt, current, frequency, etc.
Quality ~ The capability of the instrument; the measurement knowledge and suitable result,
linearity, accuracy, precision.
Instrument ~ Choose a suitable instrument: multimeter, oscilloscope, etc.
During measurement:
Quality ~ Make sure that the chosen instrument is the best. Keep it in the right position
during experiment; decide on the suitability of measurement.
Safety first ~ Take care: electric shock, overload effect, limitation of instrument.
Sampling ~ See the changing of parameter during measurement, which value should be taken
when the parameter keeps on changing. Take enough samples till it is accepted.
After measurement:
Every data must be analyzed, statically, mathematically and the result must be accurately
recorded.
4
SEM 2:06/07
Measurement
DNT 121 Instrumentation &
Lab 1: Introduction to Instrumentation & Measurements
6.5
Error in Measurement
1. Absolute error,
where
Yn= actual value
Xn = measured value
n = nth experiment
2. Percentage of error,
3. Relative accuracy,
4. Percentage of relative accuracy,
5. Precision,
where
= measured value of the nth measurement
= average of nth measured values =
n
Note: If the measurement is accurate, it must also be precision; however, a precision
measurement may not always be accurate.
6.6
Statistical Analysis of Error in Measurement
a) Arithmetic mean,
where
Xn= nth reading taken
n = total number of readings
b) Deviation from the mean,
Note: Deviation may be positive ‘+’ or negative’-‘
5
SEM 2:06/07
Measurement
DNT 121 Instrumentation &
Lab 1: Introduction to Instrumentation & Measurements
c) Average deviation,
where:
= absolute value of deviation
n = number of reading
Note: Highly precise instrument yield a low average deviation between readings
d) Standard deviation,
4.0
PROCEDURE
4.1
Error Caused by Component Tolerance
a) Set up the experimental circuit as shown in Figure 3:
Figure 3
b) Connect the voltmeter across Rb and adjust the input voltage, Vin until the output
voltage, Vo is exactly 10V. Record the value of Vin in the table provided. Do not
change Vin throughout the remainder of the experiment.
c) Replace the resistor with one of the 2.2kΩ from the set of given resistors and
again record the value of Vo in data table provided.
d) Place each of the remaining 2.2kΩ resistors in the circuit, one at a time and record
the value of Vo for each resistor. Repeat this step for 6 sets of 2.2kΩ resistor.
6
SEM 2:06/07
Measurement
DNT 121 Instrumentation &
Lab 1: Introduction to Instrumentation & Measurements
e) Using the voltage divider formula calculate the value of Rb for each of the 6
resistors. Record in the Table 3.
f) Calculate the average value of Rb. Record in Table 3.
g) Calculate the percentage of error for the average value of Rb. Record in Table 3.
4.2
Error in Reading
a) Each student measures and records the value of the resistor provided, using the
multimeter.
b) Record all the data from the measurement in the Table 4.
c) Calculate the average of the readings of resistance value measured. Record in
Table 4.
d) Calculate the percentage of error for the average resistance calculated. Record in
Table 4.
4.0
RESULT
PART A: Introduction to Electrical Instrument & Measurements
Table 1:
Actual Resistor
Value (Ω)
R1
500
R2
2.2k
R3
470k
Measured
Resistor Value
(Ω)
Range
Table 2:
Voltage Drop (Volt)
Current (A)
R1
R2
R3
7
SEM 2:06/07
DNT 121 Instrumentation & Measurement
Lab 1: Introduction to Instrumentation & Measurements
PART B: Error Measurement
Table 3: Error Caused by Component Tolerance
Calculated
Resistor
Value, Rb (Ω)
Vin= __V
Measured Vo
(Volt)
Average
value of
Rb , (Ω)
Percentage of
error for the
average value
of Rb
R1
R2
R3
R4
R5
R6
Table 4: Error in Reading
Measured
Resistor Value, Rb
(Ω)
Average
value of
Rb , (Ω)
Percentage of
error for the
average value
of Rb
R1
R2
R3
R4
R5
R6
8
SEM 2:06/07
5.0
DNT 121 Instrumentation & Measurement
Lab 1: Introduction to Instrumentation & Measurements
CALCULATION
Note: Show related calculation here
9
SEM 2:06/07
5.0
DISCUSSION
6.0
CONCLUSION
DNT 121 Instrumentation & Measurement
Lab 1: Introduction to Instrumentation & Measurements
10