Piyadanai Pachanapan, 303251 EE Instrument

1
????????? ??? ????????????? Sensor and Transducers
Piyadanai Pachanapan, 303251 EE
InstrumentMeasurement, EECPE, NU.
2
???????

• ???????????????????????????????????????????

• ??????????????????????????????????????

• ????????????????????? (Temperature Transducer)

• ???????????????? (Force Transducer)

• ????????????????????? (Light Transducer)

3
???????? (sensor)

• ???????????????????????????????????? ????
  ??????? ???????? ??? ???

• ????????????????? ????????????????????????????
  ??????????? ??????????? ???????????? ?????

4
Thermocouple Thermistor
Photo resistor
5
Strain Gauge
6
????????????? (Transducer)

• ?????????????????????????????????????????????????
  ????????? ??????????????? ????????????????????????
  ?????????????????? ????????????????????

• ???????????????????????

- ??????????????????????????
- ???????????????????
7
????????????? (Transducer)
Measurand
Transducer
Electrical Output
Excitation
8
Loading Transducer by Strain Gauge
9
????????????????????? Temperature Transducer
10
(No Transcript)
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(No Transcript)
12
???????????????????????

• ?????????????? (Thermocouple)

• ???????? (RTD)

• ????????????? (Thermistor)

13
??????????????? (Thermocouple)

• ?????????????? 2 ????????????????????????????????
  ?????????????????????????????

• ?????????????????????????????????????
  ???????????????????????????????????????

• ????????????????????????????? ???????????????????
  ?????????????????????????????????????????????????
  ?????? ?????? (Seebeck Voltage)

14
A
B
Seebeck Voltage
15
??????????????????????????????????????????????????
??????????????????????? ????????????????????
16
???????????????????????????
17
(No Transcript)
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T1, T2
19
(No Transcript)
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(No Transcript)
21
????????????? (Reference Junction)

• ?????????????? ??????????????????????????????????
  ??????

• ???????????????????? ? ??? Reference Junction ??
  2 ???

1. ??????????????????? ????????????? ? ??? Reference
   ??? 0oC

2. ???????????????????? 0oC ??????????????????????
???
22

1. ??????????????????? ????????????? ? ??? Reference
   ??? 0oC

23
2. ???????????????????? 0oC ??????????????????????
???
thermistor
24
??????????????????????????

• ??????????????????????????????????????
  ????????????????????????????????????????

• ??????????????????????????????????? (Stable)
  ??????????????????????????????

• ?????????????????????????????????????????????????
  ????????

25
???????????????????????
http//www.capgo.com/Resources/Temperature/Thermoc
ouple/Thermocouple.htmlLinearisation
26
(No Transcript)
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????????????? Thermocouple Transducer
28
Poor Conductor of Electricity But a good
conductor of Heat
??????????
??????????????????????????
Isothermal block
29
?????????????????????????????? (??????)
????????????????????
????????????????? ??? ????????????????? T1-T2
30
???????? (Resistance Temperature Detector, RTD)

• ????????????????????????????????????????????????

• ???????????????????????????????????????????
• (-182.92oC) ?????????????????????????????
  (630.74oC)

31
???????????????????? ??????????????????
????
?????
- ???????????????????????? ??????????? toC
- ???????????????????????? ??????????? 0oC
- ????????????????????????????????????????????????
?????????????? 1oC
(Temperature Coefficient of Resistancd)
32
(No Transcript)
33
(No Transcript)
34
http//www.omega.com/rtd.html
35
????????? RTD
???????? RTD
http//www.capgo.com/Resources/Temperature/RTDs/RT
D.html
36
(No Transcript)
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??????????????????? RTD
R1
R2
R3
38
Bridge Circuit with a RTD
39
-
R Ratio Arms
?????
Rx Probe resistance (at temperature x)
Rs Balancing arm (equal to Rx at lowest
temperature which may be variable for zero set.)
40

• ????????????????????? ????? RTD ??????????????
  0oC

(0o Setting)
?????????????????????? ???????? 0oC

• ???????????????????? ??????????????????????????

- ????????????????????? RTD
- ???????????????????
41
????????????? (Thermisters)

• ??????????????????????????????????????????? RTD

• ???????????? ??????????????? ???? ??????????????
  ????????? ????????? ???????????????????????????

• ?????????????????????????????????????????????

• ??????????????????????????????????????? RTD ???
  ??????????????????????????????????????

42
Thermister
43
??????????????????????????
44
?????????????????????????
http//www.capgo.com/Resources/Temperature/Thermis
tor/Thermistor.html
45
?????????????????????????????
T 1 / ( a b.ln(R) c.ln(R)3 )
46
??????????????????? Thermistor
47
(No Transcript)
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(No Transcript)
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(No Transcript)
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IC sensor ????????????????? (LM 335)
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LM 335
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LM 335
Precision temperature sensor (K/C/F)Mfr. ST Microelectronics This circuit is, unlike similar circuits, linear in its characteristics over the entire temperature range. If it is calibrated at 25 C, it will have an error of less than 1 C (typ) over a temperature range of 100 C. Otherwise easy to calibrate.










LM 335

LM 335
  Temp. range -40 to 100 C
  Output voltage 10 mV/K
  Current range 400 µA 5 mA
  Dynamic impedance 0.5 O
  Package TO92

53
???????????????? Force Transducer
54
???????? (Strain Gauge Load Cell)

• ???????????????? / ????????????????????????

• ??????????????????????????????????????
  ???????????????????????????????
  ?????????????????????????????????????

55
??????????????????????? ????????
??????????????????? ??????????????????????
?????????????????????? ???
??? ??? Resistivity ????????
??? ??????????????????
??? ??????????????????????
??? l ??????????? ??? R ?????????????????
56
?????????????????????
57
(No Transcript)
58
http//www.omega.com/literature/transactions/volum
e3/strain.html
59
?????????????????????????????????????????
(???????)
60
(No Transcript)
61
??????????????????? Strain Gauge Load Cell
output
input
62
???????????????? Light Transducer
63
???????????????????????

• Photo Diode

• Photo Resistance

64
Photo Diode

• ??????????????????????? ?????????????????????????
  ????????????? ???????????????????????

• ?????????????????????????????????????????????????
  ????

• ???????????????????????????????????
  ???????????????????????????????????? ?
  ??????????? (Saturation Region)

• ?????????????????? ??????????????????????????????
  ????????? ???????? (dark current)

65
PIN PhotoDiode
66
??????????????????????
67
(No Transcript)
68
(No Transcript)
69
???????????????????????????
????????? ??????????????
70
??????????????????? PhotoDiode
71
Photo Resistor/ Photo Conductive

• ?????????????????? ??????????????????????????????

• ?????????????????? semiconductor ???? Si, Ge, CdS

• ??????????????????????????????????????

72
http//ns.isp.nsc.ru/16/Renew/pgs/Science/pdf/Sheg
ai_Photoresistance20of20SiGe.pdf
Si/Ge/Si
73
(No Transcript)
74
??????????????????? Photo Resistor
Voltage Divider
75
(No Transcript)
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(No Transcript)
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(No Transcript)
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(No Transcript)
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END OF SECTION