Measurement And Instrumentation Strain Gauge Lab Sheet – Lab Report Example

Measurement and Instrumentation Strain Gauge Lab Sheet Introduction To there is a dire need for the designs to be stronger andlighter and tested in a thorough manner. This need leads to the emphasis on analyzing the subject of experimental stress and the methods that are used to measure strain. In this study, a stain gauge was attached to the bending beam. The objective of the experiment involves using the bending beam and the circuit bridge in the calibration of the strain gauge. The curve is used in ascertaining the large connecting rod mass.
Apparatus
The instruments and apparatus used in this study include sensor wire layout, volt meter wire layout, sensor box, weight cradle, connecting wires, digital or analogue reader, volt meter, battery, switch, spring balance, as shown in diagram 1.
Diagram 1: Apparatus
Procedure
The experiment was set up as shown is in diagram 2. The circuit was connected as shown in the diagram. The cables of connection were marked using their connection terminals like:
D
¼
F
Diagram 2: Experimental set up.
The meter was adjusted to zero without any weight on the arm. The weight was added and the record measured in each and every step. A graph was produced for load against the meter deflection. The whole process was repeated three times. The data was analyzed statistically and comments regarding the results made. The obtained data was used in the estimation of the connecting rod.
Results
The collected results was recorded in table 1 and table 2.
Table 1
Load (N)
Deflection I (mm)
Deflection II (mm)
Deflection III (mm)
5
12
12
12
10
26
26
26
15
40
38
38
20
50
51
52
25
68
64
67
30
80
77
78
35
92
90
90
40
100
102
104
Table 2
Deflection III (mm)
Load (N)
12
5
26
10
38
15
52
20
67
25
78
30
90
35
104
40
Graph 1
Discussion and conclusion
The obtained result shows the application of load and measurements of specific strain on individual member of machine or structure. In this case, the relationship between the stress and strain ensures that the stress remains in the allowable limits for the used material. Once the load was applied, the body started to deform. In a general case, the deformation is referred to as strain. This strain is typically measured using the strain gauge. The obtained strain are positive. The strain shown in the results is a fractional change, considered being directly measurable. This kind of strain is referred to as normal strain (Husein, 2012).
The objectives that were set for this experiment were realized. The experimental values were similar to the theoretical reading with some slight variations. These variations were caused by the existence of experimental errors. Some of the experimental errors include interference by air resistance, parallax, faultiness of the apparatus, and wrong calculations (Bobit, 2010). The experimental errors can be corrected by performing the experiment in a vacuum so as to avoid the air resistance interference, the experiment should be done at least three times and an average determined to avoid the errors due to parallax, and checking the apparatus to ascertain the efficiency of the apparatus before the start of the experiment. This will help to minimize the experimental errors.
References
Bobit, B., 2010. Control engineering instrumentation design studies. New York: Mcgraw Hill
Husein A., 2012. Measurement and instrumentation. Oxford: Oxford University Press.