Measurement of Thermal Properties for biological tissue
Measurement of Thermal Properties for biological tissue
Temperature Measurement ·Thermometer probe o Sensitivity o Accuracy o Stability o Response time o Passivity o Size
Temperature Measurement • Thermometer probe Sensitivity Accuracy Stability Response time Passivity Size
Liquid-in-glass (volume change) o Mercury ●-380Cto356oC o Ethyl alcohol low temperature (down to -200C)
Liquid-in-glass (volume change) Mercury -38 oC to 356 oC Ethyl alcohol low temperature (down to -200 oC)
Platinum Resistance Thermometer o Resistance change R(刀/R(To)=1+aT+bT2
Platinum Resistance Thermometer Resistance change R ( T)/ R(T 0) = 1 + a T + bT2
Thermal Couples o Seebeck effect: when a conductor is placed in a temperature gradient,electrons diffuse along the gradient and an emf or thermal voltage is generated BLACKENED JUNCTION METAL 1 Y SHIELDED VOLTMETER REFERENCE JUNCTION 1区 METAL2 affected by:electromagnetic fields AT=∑ay" Precision:0.1C n=0 as fine as 10um in diameter
Thermal Couples Seebeck effect: • when a conductor is placed in a temperature gradient, electrons diffuse along the gradient and an emf or thermal voltage is generated • affected by: electromagnetic fields Precision: 0.1 o C as fine as 10um in diameter 0 N n n n T aV