Transcript
Experimental data and result sheet
Experiment 4
Dynamic Response of Thermometers
Graph numbers
System Respond Type
Constant Time (s)
Dead Time (s)
Cold Water to Hot water
Graph1
First order
7.25
----
Graph2
First order
8.16
----
Graph3
First order
2.58
----
Graph4
----
----
----
Hot Water to Cold Water
Graph1
First order
20.58
----
Graph2
First order
17.84
----
Graph3
Second order
11.35
4
Graph4
Second order
30.42
3
Room Air to Hot Air
Graph1
Second order
16.01
6
Graph2
Second order
14.65
5
Graph3
First order
11.13
----
Graph4
First order
10.15
----
Hot Air to Room Air
Graph1
First order
52.34
----
Graph2
First order
41.84
----
Graph3
First order
51.22
----
Graph4
First order
43.26
----
Part 1. Cold water to hot water
Graph 1
Graph 2
Graph 3
Graph 4
Part 2 Hot water to cold water:
Graph 1
Graph 2
Graph 3
Graph 4
Part 3. Room Temperature to hot air
Graph1
Graph2
Graph3
Graph4
Part 4. Hot Air to Room Temperature
Graph1
Graph2
Graph3
Graph4
Calculations:
Sample calculation for the temperature respond sensor with respect to time for part3
RTD1
T = Tf-Ti
= (109.1211- 24.13443) oC
= 84.98667 oC
Ti = (0.368 x 84.98667) + 24.13443oC
= 55.4095 oC
?=16.158-55.78775-55.409555.78775-53.2486516.158-15.158= 16.009 s
The Dead time = 6
RTD2
T = Tf-Ti
= (109.8047- 24.52506) oC
= 85.27964 oC
Ti = (0.368 x 85.27964) + 24.52506 oC
= 55.90797 oC
?=15.158-57.25261-55.9079757.25261-54.6158515.158-14.158= 14.6480 s
The Dead time =5
Since the TC1 and TC2 both first order respond so the time constant was calculated:
TC1
T = Tf-Ti
= (92.65461- 24.47288) oC
= 68.18173 oC
Ti = (0.368 x 68.18173) + 24.47288 oC
= 49.5638 oC
?=11.158-50.29114-49.5638 50.29114-47.8814411.158-10.158= 11.1254 s
TC2
T = Tf-Ti
= (110.211- 24.12863) oC
= 86.08237 oC
Ti = (0.368 x 86.08237) + 24.12863 oC
= 55.8069 oC
?=10.158-55.82055-55.8069 55.82055-53.0450910.158-9.158= 10.15308 s
Note: the same steps had been followed for calculating the constant time and dead time (for the second order respond) for all of the parts 1,2&4 as shown in part 3.
Discussion
The purpose of this lab is to determine the difference between the two type’s sensors RTD, TC when these sensors were exposed to the same temperature and pressure conditions. In the first part of the lab the temperature readings were taken with respect to time under the condition of cold water to boiling water, all of the three temperature sensors (RTD1, RTD2 and TC1) were first order respond. However, the TC2 was responding slightly inaccurate to the changes in the temperature measurements of the water. The second part of the experiments, the RTD1 and RTD2 had a first respond, while the TC1 and TC2 had a second order respond. Therefore, the dead time for the TC1 and TC2 was found to be (4 and 3s ) respectively which indicated that the RTD1 and RTD2 for temperature reading from hot water to cold water were more sensible respond than the thermocouple1 and 2. The temperature reading from air at room temperature to hot air in the third part of the experiments the two types of sensors responded differently. The RTD1 and RTD2 had a second order temperature sensor responds but TC1 and TC2 had first order respond that showed the thermocouple 1 and 2 were more sensible comparing to the RTD1 and 2. Finally, for the part of hot air to room temperature air all of the four sensors had a first order response which illustrated that for the last condition all the sensors were equal sensible.
