(Resistance Temperature Detectors; RTD) ( Positive Temperature
Coefficient ; PTC ) ( Resistance Temperatures )
RTD 0 oC RTD Metal Sheath
RTD
RTD 2 RTD Wheathstone Bridge Rt RTD 3 R1, R2, R3
1 RTD 2 1 Bridge RTD (Rt) 0 0C Rt Rt Bridge Rt Rt Bridge RTD 2
RTD RTD 2 RTD 3
2 RTD 3 RTD 3 3 3 , R1, R2 R3
r1 r3 Rt RTD 3 RTD 2 RTD 4 RTD 4 Bridge 4 4, RTD 3
3 RTD 4 1. 2. 3. (I2R) 2-Wire Signal Transmitter
Signal Transmitter 2 Output Transmitter Power Supply Signal
Transmitter Output Signal Transmitter 4-20 mA Transmitter
2-Wire Signal Transmitter4-Wire Signal Transmitter
Signal Transmitter 2 Power Supply 2 Output 4 Wire Signal
Transmitter
Output
Output
(Thermocouple) (emf) 2 () Thomas Seebeck ..1821 Thermocouple
2
4 (Thermoelectric Effect)
1. (Seebeck Effect)
1. emf. 2. emf. 3. emf.
= ; volts/K
T1, T2 = ; K
2. (Peltier Effects) (T2) (T1) (Peltier effect)
5 (Reference Junction) Thermocouple reference junction 2 . 2 2
(Vout) Isothermal Block
6 Thermocouple
Ice bath reference point 0 (standard table) . ice bath reference
junction compensate reference junction
7 reference junction (Characteristic of Standard
Thermocouples)
1. (Sensitivity) NBS 100 mV
8 2. (Construction) 8 : (peltier element) #10 # 30 0.02 mm
(micro wire) 3. (Range)
1 4. (Time Response) 5. (Signal Conditioning) (Characteristic in
Application of Thermocouple Standard Type) 7 ANSI ASTM1. S 2. R 3.
B 4. J 5. K 6. T 7. E
8 LAB INC101/102
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1.2. Thermocouple 3. RTD1. Digital Multimeter
serial NO Input. .2. Digital Thermometer
serial NO Input.. ... 3. , , Thermocouple type K, RTD Pt100 1
Thermocouple1. Reference Junction Reference Junction Thermocouple
Thermocouple (mV) Thermocouple type Digital Multimeter
2. Thermocouple mV Digital Multimeter Digital Thermometer 80oC
90oC Thermocouple Digital Thermometer% error
80oC
90oC
3. Thermocouple Reference Junction 0oC Reference Junction
Thermocouple 80oC 90oC Thermocouple Digital Thermometer% error
80oC
90oC
2 RTD 2.1 RTD 2 RTD
2.1 1. RTD High Resolution Multimeter
2. RTD ( 80 oC )3. High Resolution Multimeter 2 Auto range4.
Digital Thermometer 5. High Resolution Multimeter Digital
Thermometer 6. () ( oC ) Digital Thermometer ( oC )Error (%)
2.2 RTD 1. Industrial Instrument Transmitter, Power Supply High
Resolution Multimeter Loop 2 wires, RTD
2. High Resolution Multimeter DCA AUTO Range3. RTD( 80 oC )
Digital Thermometer 4. RTD Digital Thermometer 5. RTD Digital
Thermometer (mA) RTD( oC ) Digital Thermometer ( oC )Error (%)
1. Reference Junction Thermocouple Reference Junction
2. RTD 2-wires 3-wires EMBED Equation.3
EMBED Equation.3
Digital Multimeter
_1262156405.unknown
_1262156312.unknown
