Medical Instrumentation HW 4 200456 Lim Myeong Jun

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Medical Instrumentation HW #4 200456 Lim Myeong Jun

Medical Instrumentation HW #4 200456 Lim Myeong Jun

Contents Electromagnetic Spectrum Radiation Thermometer

Contents Electromagnetic Spectrum Radiation Thermometer

Electromagnetic spectrum 1. Audio frequency (20~20, 000 Hz) λ : Wave length c :

Electromagnetic spectrum 1. Audio frequency (20~20, 000 Hz) λ : Wave length c : Speed of light f : Frequency L = 10, 000 km

Electromagnetic spectrum 2. Radio frequency 2 -1. Low frequency : 30 k. Hz ~

Electromagnetic spectrum 2. Radio frequency 2 -1. Low frequency : 30 k. Hz ~ 300 k. Hz (10 km ~ 1 km) 2 -2. Medium frequency : 300 k. Hz ~ 3 MHz (1 km ~ 100 m) 2 -3. High frequency : 3 MHz ~ 30 MHz (100 m ~ 10 m) 2 -4. Very high frequency : 30 MHz ~ 300 MHz (10 m ~ 1 m) 2 -5. Ultra high frequency : 300 MHz ~ 3 GHz (1 m ~ 0. 1 m)

Electromagnetic spectrum L = 10 m c = 3. 8 x 108 m/s Vs(t)

Electromagnetic spectrum L = 10 m c = 3. 8 x 108 m/s Vs(t) t t Time delay : 1/3 x 10 -7 s Length of antenna = λ/2 • One of the most important reason for using high frequency signal is that can reducing antenna length.

Electromagnetic spectrum 3. Microwave 3 -1. Centimeter wave : 3 GHz ~ 30 GHz

Electromagnetic spectrum 3. Microwave 3 -1. Centimeter wave : 3 GHz ~ 30 GHz (10 cm ~ 1 cm) 3 -2. Millimeter wave : 30 GHz ~ 300 GHz (1 cm ~ 1 mm) 3 -3. Sub millimeter wave : 300 GHz ~ 3 THz (1 mm ~ 0. 1 mm)

Electromagnetic spectrum 4. Infrared 4 -1. Far infrared : 10 -4 m ~ 10

Electromagnetic spectrum 4. Infrared 4 -1. Far infrared : 10 -4 m ~ 10 -5 m (100 um ~ 10 um) 4 -2. (Intermediate) infrared : 10 -5 m ~ 10 -6 m (10 um ~ 1 um)

Electromagnetic spectrum 5. Visible light : ~nm Red : Longest λ … Violet :

Electromagnetic spectrum 5. Visible light : ~nm Red : Longest λ … Violet : Shortest λ

Electromagnetic spectrum 6. UV(Ultra violet) 7. X-ray Frequency ↑ 8. γ-ray ∝ Energy ↑

Electromagnetic spectrum 6. UV(Ultra violet) 7. X-ray Frequency ↑ 8. γ-ray ∝ Energy ↑ E : Energy h : Plank constant ν : Frequency

Electromagnetic spectrum Visible light Red has long λ and Blue has short λ Micro

Electromagnetic spectrum Visible light Red has long λ and Blue has short λ Micro wave (Infrared) Although we can’t see the light(micro wave), all of the object radiate micro wave

Radiation thermometer Shutter Lense Op-amp IR sensor mp ADC LCD Battery IR sensor (Pyroelectric

Radiation thermometer Shutter Lense Op-amp IR sensor mp ADC LCD Battery IR sensor (Pyroelectric sensor) -> No dc response Sensor Input Fig. Radiation Thermometer Sensor Output a b a : Shutter on b : Shutter off

Thanks for your attention!

Thanks for your attention!