Mechanical Measurements Report
NAME / Ahmed Mohamed Shehata Mahmoud
SEC / 2
Dr/ omar
Abstract-Aim
1-Construction of thermocouple
2-calibration of thermocouple
3-calibration of electrical resistance thermometer
Nomenclature
)T)
The temperature of the substances
(Celsius)
)R)
The resistance of a conductor
(ohm)
)emf)
measuring the emf of the free terminal of thermocouple
(mV)
Objectives
1-construct a calibration curve for the thermocouple
2- Construct a calibration curve of electrical resistance thermometer
Introduction
Temperature is a thermodynamic property of a body, which tell us whether the body is hot or
cold. The measurement of temperature is required in many fields like measuring the
temperature of a household and parts of human body …etc.
It is required to control temperature of certain systems so that the temperature of these
systems remain within a certain range.
Tools
1-Glass thermometer
2-pressure gage thermometer
3-Differential Expansion thermometer
4-Electrical Resistance thermometer
5-Thermocouples
6-Optical Pyrometers
7- Radiation Pyrometers
Method
1-Make the first junction between the two dissimilar metals by welding
2-Make another junction by the same way
3-Put one junction in the hot source, which its temperature wanted to be measured
4-Put the other junction in ice bath
5-Connected the two free ends of thermocouple to millivolt meter for measuring emf
6-The thermocouple is ready now for calibration
Experimental results
Num.of reading
1
2
3
4
5
6
7
8
9
10
11
12
13
Temperature,C
74
71
65
64
62
60
58
55
53
51
49
44
40
Table (1)
Y=.04x
Y= emf
X=T
emf ,mV
2.3
2.2
2
1.9
1.8
1.7
1.6
1.5
1.4
1.3
1.2
1.1
1
3
emf(mv)
2.5
2
1.5
1
0.5
0
0
10
20
30
40
50
60
70
80
90
Temperature (C)
Figure(1)
Discussion
1-The data of temperature is taken over the range (0 to 100 Celsius)
**The data of emf is taken over the range (0 to 5 mV) as shown in table (1)
- The result is depicted in figure 1
** The data of Resistance is taken over the range (100 to 128 ohm) as shown in table (2)
-The result is depicted in figure2
Conclusion
Using the statistical methods we were able to assemble the assemble the results and
put them in the table and draw the calibration curve for the thermocouple electrical and
resistance thermometer
References
-Experimental methods for mechanical engineering P-Holman