DEPARTMENT OF ELECTRICAL ENGINEERING
NATIONAL INSTITUTE OF TECHNOLOGY, ROURKELA-769008
Measurement and Instrumentation Laboratory
EXPERIMENT-2
Aim of the Experiment:
Measurement of force using strain gauges.
Apparatus required:
Sl.No. List of the Equipment Specifications Quantity
01 Experimental Kit ST2304 01
02 Digital Multimeter LCR Type 01
03 Weight 50 gm - 500 gm -----
04 Screw Driver Taparia91 01
05 Patch cords 1mm As per required
Circuit Diagram:
DEPARTMENT OF ELECTRICAL ENGINEERING
NATIONAL INSTITUTE OF TECHNOLOGY, ROURKELA-769008
Measurement and Instrumentation Laboratory
Procedure:
1. Switch ‘On’ the trainer power supply.
2. Observe the reading of the display. It should be 000.
3. If the display reading is not 000, then adjust the offset to null.
4. Place a weight of 50 gms on the cantilever's free end and observe the display reading. It indicates strain
developed on the cantilever in strain.
5. Calculate theoretical strain by the formula.
(6 F L) / (W T2 Y),
Where, F = force (N)=mg
m = mass (Kg),
g = acceleration due to gravity (9.8m/Sq. sec),
DEPARTMENT OF ELECTRICAL ENGINEERING
NATIONAL INSTITUTE OF TECHNOLOGY, ROURKELA-769008
Measurement and Instrumentation Laboratory
L = Length (m)=20cm, w = width (m)=2.5cm,
T = thickness (m)-0.16cm,
Y = Young's modulus (N/Sq. m) = 200109 N/m2 for stainless steel.
6. Repeat those mentioned above for different weights as shown in the following table and complete the
table.
7. Plot the graph between weight (gm) and display reading (µ-strain).
8. Observe the graph. And point out the linear portion of the graph. This is the linear range of operation.
9. Calculate:
(Maximum deviation of display reading from the theoretical strain ) ∗ 100
% Linearity =
Theoretical strain for 500 gm
Precaution:
1. Wear shoes before coming to the lab.
2. Before taking the reading, make sure that the cantilever is not vibrating.
DEPARTMENT OF ELECTRICAL ENGINEERING
NATIONAL INSTITUTE OF TECHNOLOGY, ROURKELA-769008
Measurement and Instrumentation Laboratory
Observation Table:
Offset: _______
Gain: ________
Theoretical Deviation of
S. No. Weight(gm) Strain(€*10-6) Display reading display reading
Form Theoretical
(€*10-6) strain
1. 0
2. 50
3. 100
4. 150
5. 200
6. 250
7. 300
8. 350
9. 400
10. 450
11. 500
Calculations:
(Maximum deviation of display reading from the theoretical strain ) ∗ 100
% Linearity =
Theoretical strain for 500 gm
Graph:
Plot the graph: strain (display reading) on Y-axis v/s weight (gm) on X-axis.
Conclusion:
To be written by the students.
Discussion on the result:
Write your comment on the results obtained. And discuss the deviation, if any.
