Dynamic Response of Thermometers

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.