DAT｜感應器功能組件 Sensor Functional Block｜S2 科技原理 Technological Principles

紅外線感應器 Infra-red sensor

探測原理 Working Principle

發射器發射紅外線後由它碰到的物體將紅外線反射，並由接收器接收。測量紅外線在感應器與物體之間經過的時間計算距離。

The emitter emits infrared and the light will bounce back from the object it hit and receive by the receiver. The time lapses between the sending and receiving of the of the sensor and object is measured and the distance calculated.

限制 Limitations

容易受各種熱源、光源干擾。

Easily interfered with by different heat and light sources.

環境溫度和人體温度接近時，探測靈敏度會下降，造成短暫失靈。

When the temperature of the environment is close to body temperature, the sensing sensitivity decreases, causing the sensor to be out of order temporarily.

例子 Examples

參考試題：感應式水龍頭 2024-DAT-P1-Q3(d)(ii)

當使用者將手放在水龍頭出水口下方，便會阻擋紅外線裝置所發出的紅外線光束。使用者的手會反射光束到紅外線接收器，紅外線裝置便會發出信號使水龍頭出水。

When users put their hands under the water opening, the infra-red light emitted by the infra-red device will be blocked. The hands will reflect the light to the infra-red receiver, and the infra-red device will then give signal to the faucet to supply water.

參考試題：戶外自動感應燈 2023-DAT-P1-Q2(b)

當使用者進入戶外自動感應燈感應範圍時，使用者便會阻擋紅外線裝置所發出的紅外線光束。使用者的身體會反射光束到紅外線接收器，紅外線裝置便會發出信號啟動燈光裝置。

When users enter the detection range of the outdoor automatic sensor light, the user will block the infra-red light emitted by the infra-red device. The user’s body will reflect the light to the infra-red receiver, and the infra-red device will then send a signal to activate the lighting system.

參考試題：非觸式樓層按鈕面板識別哪個按鈕被選擇 2022-DAT-P1-Q3(a)

安裝在不同高度的紅外線感應器能測出所選按鈕屬於哪一列；選擇的按鈕與紅外線感應器的距離能測出按鈕是屬於哪一行。

The infrared sensors installed at different heights determine which row the selected button belongs; the distance between the selected button and the infrared sensor distinguishes at which column the selected button belongs.

超聲波感應器 Ultrasonic sensor

探測原理 Working Principle

發射器發射聲波並從離它最近的物體反射並由接收器接收回聲；測量聲波在感應器與物體之間往返經過的時間計算距離。

The transmitter emits sound wave and the wave will bounce back from the nearest object and receive by the receiver. The time lapses between the sending and receiving of the ultrasonic signal of the sensor and object is measured to calculate the distance.

限制 Limitations

不適合在水下使用。

Not suitable for use underwater.

軟質材料（如布料、泡棉）無法有效反射聲波，導致距離測量不準確。

Soft materials (such as cloth and foam) cannot effectively reflect sound waves, resulting in inaccurate distance measurements.

例子 Examples

參考試題：扶手電梯智能系統 2021-DAT-P1-Q2(c)(i)

發射器發射聲波，聲波傳送到乘客的腿部時後反射聲波。接收器接收回聲後，測量聲波在感應器與物體之間往返的時間並計算距離。乘客到達扶手電梯的範圍時，測量到的距離減少，表示檢測到乘客的存在，從而發出信號提升扶手電梯的運行速度。

The transmitter emits sound wave and the wave will bounce back from the passenger’s legs and receive by the receiver. The time lapses between the sending and receiving of the ultrasonic signal of the sensor and object is measured and the distance calculated. When the passenger enters the range of the escalator, the measured distance decreases, indicating the presence of the passenger, and a signal is sent to increase the escalator’s speed.

參考試題：探測垃圾桶是否已滿 2020-DAT-P1-Q2(a)

發射器發射聲波，聲波傳送到物體（垃圾）後反射聲波。接收器接收回聲後，測量聲波在感應器與物體之間往返的時間並計算距離。垃圾量增加時，測量到的距離減少，表示垃圾桶將滿。

The transmitter emits sound wave and the wave will bounce back from the nearest object (rubbish) and receive by the receiver. The time lapses between the sending and receiving of the ultrasonic signal of the sensor and object is measured and the distance calculated. When the amount of rubbish increases, the measured distance decreases; this indicates that the bin is getting full.

光敏感應器 Light sensor

探測原理 Working Principle

根據接收到的光強度改變其電阻或電壓輸出。當環境光變化時，感應器將此改變轉變成輸出信號。

Change its resistance or voltage output according to the intensity of received light. When the ambient light changes, the sensor converts this change into the output signal.

限制 Limitations

強烈陽光或其他光源可能會干擾感應器的判斷，影響其準確性。

Strong sunlight or other light sources may interfere with the sensor’s detection, reducing accuracy.

在光線不足的情況下，感應器可能無法正常運作或反應不靈敏。

In dim environments, the sensor may not function properly or may respond slowly.

例子 Examples

參考試題：食品加工機物料感應 2010-TECH STUD-P1-Q4(f), 自動貨物分流系統 2008-TECH STUD-P1-Q3(a)

光敏感應器是一種可變電阻，它的電阻值會根據光線的強弱程度而改變。當物件經過光敏感應器時，光線因受物件阻擋而改變感應器所接收的光度，因而探測到物件經過，從而控制切割等加工程序／將貨物送往不同路徑或分類區。

Light sensor is a type of variable resistor whose resistance changes according to the intensity of light. When an object passes by the light sensor, the light is blocked by the object, changing the amount of light received by the sensor. This allows the system to detect the presence of the object and control processes such as cutting in food processing / directing goods to different paths or sorting areas.

溫度感應器 Temperature sensor

探測原理 Working Principle

溫度感應器系統中的回輸功能將部分輸出信號回饋至輸入端，比較信號的差別，從而調整輸出。

The feedback function in a temperature sensor system sends part of the output signal back to the input, compares the difference between the signals, and adjusts the output accordingly.

例子 Examples

參考試題：乾衣機 2009-TECH STUD-P1-Q2(d)

壓力感應器 Pressure sensor

探測原理 Working Principle

根據接收到的壓力改變其電阻或電壓輸出。當壓力改變時，感應器將改變轉變成感應器的輸出信號。

Change its resistance or voltage output according to the received pressure. When the pressure changes, the sensor converts this change into the output signal.