temperature measurement using sensors and signal conditioning
DESCRIPTION
asdadsadsTRANSCRIPT
-
Temperature Measurement using sensors and signal conditioningMichael MansellKen Dudeck (Faculty Sponsor)
-
Topics of DiscussionTypes of temperature sensorsThe CK101 LCD Temperature MeterOur circuit design
-
Types of temperature sensorsRTD (Resistance Temperature Detector)ThermistorThermocouple
-
RTD, the basicsHow it works:Utilizes the fact that resistance of a metal changes with temperature.Make up:Traditionally made up of platinum, nickel, iron or copper wound around an insulator.Temperature range:From about -196C to 482C.Thin Film RTD
-
RTD Advantages and DisadvantagesAdvantages:StableVery accurateChange in resistance is linearDisadvantages:ExpensiveCurrent source requiredSmall change in resistanceSelf heatingLess rugged than thermocouples.
-
Thermistor, the basics ofHow it works:Like the RTD a thermistor uses the fact that resistance of a metal changes with temperature.Make up:Generally made up of semiconductor materialsTemperature Range:About -45C - 150CThermistor
-
Thermistor Advantages and DisadvantagesAdvantages:Very sensitive (has the largest output change from input temperature)Quick responseMore accurate than RTD and ThermocouplesDisadvantages:Output is a non-linear functionLimited temperature range.Require a current sourceSelf heatingFragile
-
Thermocouple, some more basicsHow it works:Made up of two different metals joined at one end to produce a small voltage at a given temperature.Make up:Made of up two different metals. Ex: A type J is made up of Iron and Constantan.Temperature RangeType J: 0C to 750CA few Thermocouples
-
Thermocouple Advantages and DisadvantagesAdvantages:Self Powered (does not require a current or voltage source)RuggedInexpensiveSimpleDisadvantages:Extremely Low Voltage output (mV)Not very stableNeeds a reference point
-
Lets Experiment!In lab a RTD, thermistor, and thermocouple were placed in a beaker of 750mL of water and readings were taken from 19C to 80C.The next two slides show the results.
-
The Data (some of it)
-
A little easier to read
Chart1
-0.1
-0.1
0
0
0
0.1
0.1
0.1
0.2
0.2
0.3
0.4
0.5
0.7
0.7
0.8
0.9
1
1.3
1.5
1.5
1.6
1.7
1.8
1.9
2
2.1
2.2
2.3
2.4
2.5
2.6
2.7
2.8
2.9
Temperature (C)
Voltage (mV)
Thermocouple
Data
TemperatureThermocoupleRTDThermistorVoltage Gain (Thermocouple)Voltage Gain (RTD)
(ohms)(kilo-ohms)using formula [V]using formula [V]
19-0.10108.00105.60-0.50410.030
20-0.10108.4099.80-0.50410.064
210.00108.7094.200.00010.090
220.00109.0088.200.00010.115
230.00109.5083.800.00010.158
240.10110.0079.700.50410.200
250.10110.4075.900.50410.234
260.10110.9073.300.50410.277
270.20111.3070.001.00810.311
280.20111.5068.401.00810.328
290.30112.0063.401.51210.370
300.40112.9060.502.01610.447
320.50113.2054.802.52110.472
340.70114.1049.203.52910.549
360.70114.8045.503.52910.608
380.80115.7043.104.03310.685
400.90116.3039.104.53710.736
421.00117.0035.905.04110.795
481.30119.4027.506.55310.999
501.50120.3025.257.56211.076
521.50121.1023.337.56211.144
541.60121.8022.218.06611.203
561.70122.4020.698.57011.254
581.80123.4018.669.07411.339
601.90123.9017.699.57811.382
622.00124.8015.8910.08211.458
642.10125.6014.7010.58611.526
662.20126.3014.1811.09011.586
682.30127.1012.8811.59411.654
702.40127.8011.9312.09811.713
722.50128.5011.2912.60311.773
742.60129.4010.4713.10711.849
762.70130.209.7413.61111.917
782.80130.909.0014.11511.977
802.90131.508.5914.61912.028
Voltage Gain Data for ThermocoupleVoltage Gain Data for RTD
Rb:70000Vin:0.85
Ra:1000Ra:10
Graphs
Graphs
-0.1
-0.1
0
0
0
0.1
0.1
0.1
0.2
0.2
0.3
0.4
0.5
0.7
0.7
0.8
0.9
1
1.3
1.5
1.5
1.6
1.7
1.8
1.9
2
2.1
2.2
2.3
2.4
2.5
2.6
2.7
2.8
2.9
Temperature (C)
Voltage (mV)
Thermocouple
Sheet3
108
108.4
108.7
109
109.5
110
110.4
110.9
111.3
111.5
112
112.9
113.2
114.1
114.8
115.7
116.3
117
119.4
120.3
121.1
121.8
122.4
123.4
123.9
124.8
125.6
126.3
127.1
127.8
128.5
129.4
130.2
130.9
131.5
Temperature (C)
Resistance ()
RTD
105.6
99.8
94.2
88.2
83.8
79.7
75.9
73.3
70
68.4
63.4
60.5
54.8
49.2
45.5
43.1
39.1
35.9
27.5
25.25
23.33
22.21
20.69
18.66
17.69
15.89
14.7
14.18
12.88
11.93
11.29
10.47
9.74
9
8.59
Temperature (C)
Resistance (K)
Thermistor
Chart3
105.6
99.8
94.2
88.2
83.8
79.7
75.9
73.3
70
68.4
63.4
60.5
54.8
49.2
45.5
43.1
39.1
35.9
27.5
25.25
23.33
22.21
20.69
18.66
17.69
15.89
14.7
14.18
12.88
11.93
11.29
10.47
9.74
9
8.59
Temperature (C)
Resistance (K)
Thermistor
Data
TemperatureThermocoupleRTDThermistorVoltage Gain (Thermocouple)Voltage Gain (RTD)
(ohms)(kilo-ohms)using formula [V]using formula [V]
19-0.10108.00105.60-0.50410.030
20-0.10108.4099.80-0.50410.064
210.00108.7094.200.00010.090
220.00109.0088.200.00010.115
230.00109.5083.800.00010.158
240.10110.0079.700.50410.200
250.10110.4075.900.50410.234
260.10110.9073.300.50410.277
270.20111.3070.001.00810.311
280.20111.5068.401.00810.328
290.30112.0063.401.51210.370
300.40112.9060.502.01610.447
320.50113.2054.802.52110.472
340.70114.1049.203.52910.549
360.70114.8045.503.52910.608
380.80115.7043.104.03310.685
400.90116.3039.104.53710.736
421.00117.0035.905.04110.795
481.30119.4027.506.55310.999
501.50120.3025.257.56211.076
521.50121.1023.337.56211.144
541.60121.8022.218.06611.203
561.70122.4020.698.57011.254
581.80123.4018.669.07411.339
601.90123.9017.699.57811.382
622.00124.8015.8910.08211.458
642.10125.6014.7010.58611.526
662.20126.3014.1811.09011.586
682.30127.1012.8811.59411.654
702.40127.8011.9312.09811.713
722.50128.5011.2912.60311.773
742.60129.4010.4713.10711.849
762.70130.209.7413.61111.917
782.80130.909.0014.11511.977
802.90131.508.5914.61912.028
Voltage Gain Data for ThermocoupleVoltage Gain Data for RTD
Rb:70000Vin:0.85
Ra:1000Ra:10
Graphs
Graphs
-0.1
-0.1
0
0
0
0.1
0.1
0.1
0.2
0.2
0.3
0.4
0.5
0.7
0.7
0.8
0.9
1
1.3
1.5
1.5
1.6
1.7
1.8
1.9
2
2.1
2.2
2.3
2.4
2.5
2.6
2.7
2.8
2.9
Temperature (C)
Voltage (mV)
Thermocouple
Sheet3
108
108.4
108.7
109
109.5
110
110.4
110.9
111.3
111.5
112
112.9
113.2
114.1
114.8
115.7
116.3
117
119.4
120.3
121.1
121.8
122.4
123.4
123.9
124.8
125.6
126.3
127.1
127.8
128.5
129.4
130.2
130.9
131.5
Temperature (C)
Resistance ()
RTD
105.6
99.8
94.2
88.2
83.8
79.7
75.9
73.3
70
68.4
63.4
60.5
54.8
49.2
45.5
43.1
39.1
35.9
27.5
25.25
23.33
22.21
20.69
18.66
17.69
15.89
14.7
14.18
12.88
11.93
11.29
10.47
9.74
9
8.59
Temperature (C)
Resistance (K)
Thermistor
Chart2
108
108.4
108.7
109
109.5
110
110.4
110.9
111.3
111.5
112
112.9
113.2
114.1
114.8
115.7
116.3
117
119.4
120.3
121.1
121.8
122.4
123.4
123.9
124.8
125.6
126.3
127.1
127.8
128.5
129.4
130.2
130.9
131.5
Temperature (C)
Resistance ()
RTD
Data
TemperatureThermocoupleRTDThermistorVoltage Gain (Thermocouple)Voltage Gain (RTD)
(degrees Celcius)(mili-Volts)(ohms)(kilo-ohms)using formula [V]using formula [V]
19-0.10108.00105.60-0.50410.030
20-0.10108.4099.80-0.50410.064
210.00108.7094.200.00010.090
220.00109.0088.200.00010.115
230.00109.5083.800.00010.158
240.10110.0079.700.50410.200
250.10110.4075.900.50410.234
260.10110.9073.300.50410.277
270.20111.3070.001.00810.311
280.20111.5068.401.00810.328
290.30112.0063.401.51210.370
300.40112.9060.502.01610.447
320.50113.2054.802.52110.472
340.70114.1049.203.52910.549
360.70114.8045.503.52910.608
380.80115.7043.104.03310.685
400.90116.3039.104.53710.736
421.00117.0035.905.04110.795
481.30119.4027.506.55310.999
501.50120.3025.257.56211.076
521.50121.1023.337.56211.144
541.60121.8022.218.06611.203
561.70122.4020.698.57011.254
581.80123.4018.669.07411.339
601.90123.9017.699.57811.382
622.00124.8015.8910.08211.458
642.10125.6014.7010.58611.526
662.20126.3014.1811.09011.586
682.30127.1012.8811.59411.654
702.40127.8011.9312.09811.713
722.50128.5011.2912.60311.773
742.60129.4010.4713.10711.849
762.70130.209.7413.61111.917
782.80130.909.0014.11511.977
802.90131.508.5914.61912.028
Voltage Gain Data for ThermocoupleVoltage Gain Data for RTD
Rb:70000Vin:0.85
Ra:1000Ra:10
Graphs
Graphs
-0.1
-0.1
0
0
0
0.1
0.1
0.1
0.2
0.2
0.3
0.4
0.5
0.7
0.7
0.8
0.9
1
1.3
1.5
1.5
1.6
1.7
1.8
1.9
2
2.1
2.2
2.3
2.4
2.5
2.6
2.7
2.8
2.9
Temperature (C)
Voltage (mV)
Thermocouple
Sheet3
108
108.4
108.7
109
109.5
110
110.4
110.9
111.3
111.5
112
112.9
113.2
114.1
114.8
115.7
116.3
117
119.4
120.3
121.1
121.8
122.4
123.4
123.9
124.8
125.6
126.3
127.1
127.8
128.5
129.4
130.2
130.9
131.5
Temperature (C)
Resistance ()
RTD
105.6
99.8
94.2
88.2
83.8
79.7
75.9
73.3
70
68.4
63.4
60.5
54.8
49.2
45.5
43.1
39.1
35.9
27.5
25.25
23.33
22.21
20.69
18.66
17.69
15.89
14.7
14.18
12.88
11.93
11.29
10.47
9.74
9
8.59
Temperature (C)
Resistance (K)
Thermistor
-
First test subject (The Kit CK101)Basically the same idea as our circuit design, but easier?How it worksWhy it did not work
CK101 LCD Temperature Sensor
-
How it works and what went wrongUses transistors instead of the other discussed sensor types.Uses the ICL 7106 chipProblems:Possible Bad chipCapacitors not soldered in properly.Cold solder joins leading to bad connections
-
Our designIt works!
-
Picture
-
Another Picture
-
Circuit Diagram
1
1K
49K
1K
50K
1K
1K
50K
50K
-Vin+
+-
+-
+-
+Vout-
+
-
Thermocouple
4.7F
7417
1
2
5V
15V
Fan
Relay
-
Questions or Comments?
-
My SourcesOmega.com (Info on RTDs and Thermistors) http://www.omega.com/United Electric Controls (Thermocouple, RTD, and Thermistor info) http://www.ueonline.com/Intersil (ICL 7106 Chip reference) http://www.intersil.com/