When working on projects and debugging, sensor selection is the first hurdle for engineers. Have you ever struggled with the differences and applications of the various types available?
Don’t worry! Today, we will conduct a comprehensive comparison of the five most commonly used sensors—Infrared, Hall, Photoelectric, Ultrasonic, and Temperature—to help you quickly select the right one and get started easily! Save this for quick reference; hardcore content is about to begin! 🔥
1. Infrared Pair
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Core Principle: Infrared transmission, where the emitter emits infrared light and the receiver collects the signal.
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Output Signal: Switch signal (signal present/absent)
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Features:
✅ Simple structure, low cost
✅ Suitable for transmission detection
❌ Easily affected by ambient light interference
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Typical Applications: Counting, security, automatic doors
The infrared pair is a type of infrared transmission sensor made based on the principle of infrared radiation sensors, consisting of three parts: an optical system (emitter), a detector (receiver), and a signal conditioning and output circuit. The receiver reacts to the infrared light emitted by the emitter to collect the signal.
2. Hall Sensor
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Core Principle: Hall effect, where changes in the magnetic field generate an electric potential.
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Output Signal: Digital signal (high/low level)
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Features:
✅ Extremely fast response (microsecond level)
✅ Non-contact, long lifespan
✅ High sensitivity, good stability
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Typical Applications: Motor speed measurement, position detection, current sensing
The Hall sensor is a sensor based on the Hall effect, characterized by high sensitivity, good linearity, high stability, small size, and high-temperature resistance. The requirements for speed measurement devices are strong resolution, high precision, and as short detection time as possible.
Response speed is generally around 7 microseconds, so there is no need to consider the time for the microcontroller’s loop judgment!
3. Photoelectric Switch
Core Principle: The photosensitive element receives changes in incident light and performs photoelectric conversion.
Output Signal: Switch signal
Features:
✅ Compact, high-speed, non-contact✅ Easily integrates with TTL, MOS, and other circuits✅ Wide application range
Typical Applications: Object detection, product counting, material level detection, size control, safety alarms
The photoelectric switch is a reflective or transmissive photoelectric sensor. In a reflective photoelectric switch, the light-emitting element and the receiving element are in the same plane and intersect at a certain angle, with the intersection point generally being where the object to be measured is located; in a transmissive type, the light axes coincide, and detection is achieved by the object blocking the light path.
4. Ultrasonic Sensor
Core Principle: Ultrasonic emission and reception, measuring distance by the echo time.
Output Signal: Analog/digital signal
Features:
✅ Accurate distance measurement✅ Not affected by light or color✅ Can detect over long distances
Typical Applications: Distance measurement, liquid level detection, obstacle avoidance
The ultrasonic sensor is developed based on the physical properties and various effects of ultrasonic waves in an ultrasonic field, with the most common being the piezoelectric ultrasonic probe. It uses the inverse piezoelectric effect to generate ultrasonic waves (emission) and the direct piezoelectric effect to receive ultrasonic waves (reception).
5. Temperature Sensor (DS18B20)
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Core Principle: Semiconductor temperature-sensitive element.
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Output Signal: Digital signal
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Features:
✅ Single bus, simple wiring
✅ Digital output, strong anti-interference
✅ High integration, easy to use
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Typical Applications: Environmental temperature monitoring, equipment temperature control
DS18B20 is a commonly used digital temperature sensor,with an accuracy of 0.5 degrees and a resolution of 0.0625 degrees (when stored as a 12-bit digital quantity), noting the difference between the two.
Summary of the Five Sensors (Quick Reference Table)
| Sensor Type | Core Detection Object | Output Signal | Advantages | Typical Application Scenarios |
|---|---|---|---|---|
| Infrared Pair | Infrared light (obstruction) | Switch signal | Low cost, simple structure | Counting, security, automatic doors |
| Hall Sensor | Magnetic field | Digital signal | Extremely fast response, non-contact | Motor speed measurement, position detection |
| Photoelectric Switch | Visible/infrared light | Switch signal | Non-contact, wide application | Object detection, liquid level, packaging line |
| Ultrasonic Sensor | Ultrasonic echo | Analog/digital | Distance measurement, not affected by light | Distance measurement, liquid level, obstacle avoidance |
| Temperature Sensor | Heat | Digital signal | Single bus, high integration, easy to use | Environmental temperature monitoring, equipment temperature measurement |
| (Supplement) Angle Sensor | Magnetic field angle | Analog/digital | High precision angle measurement | Rotational position, steering wheel angle |
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[This article is compiled from online sources for learning and communication purposes only; copyright belongs to the original author.]