Type of sensor - solution - Huaqiang Electronic Network

Sensors can be categorized in various ways depending on their design, function, and working principles. One common classification is based on the mechanism they use to detect and convert physical quantities into measurable signals. This includes structural-type sensors, physical-type sensors, hybrid-type sensors, and biosensors.

Structural-type sensors rely on changes in the mechanical structure of the device. For example, a capacitive pressure sensor works by detecting changes in capacitance when pressure is applied, which causes the plates to move. When used in a resonant system, this change in capacitance affects the resonant frequency, allowing for precise pressure measurement.

Physical-type sensors, on the other hand, utilize the inherent physical or chemical properties of materials. These sensors typically do not have moving parts, making them more compact and durable. They are often referred to as solid-state sensors and are widely used in applications where miniaturization is important.

Hybrid-type sensors combine both structural and physical elements to achieve more complex sensing functions. Biosensors, meanwhile, incorporate biological components such as microorganisms or tissues to detect specific biochemical reactions, offering powerful tools in medical and environmental monitoring.

Another way to classify sensors is by their composition. Basic-type sensors are single-component devices that perform a direct conversion of the input signal. Combined-type sensors integrate multiple transducers to enhance functionality. Applied-type sensors combine these basic or combined sensors with additional mechanisms to create specialized systems, such as infrared radiation sensors that use thermocouples in conjunction with heat absorbers.

Sensors can also be divided into active and passive types based on their operation. Active sensors generate a signal to interact with the measured object, such as in radar systems or radio frequency detectors. Passive sensors, however, only receive signals from the object itself, like infrared thermometers or cameras.

In terms of output, sensors can produce either analog or digital signals. Analog sensors provide continuous signals, while digital sensors output discrete values (0 or 1). Some sensors, like those using vibration, may produce periodic signals that can act as quasi-digital signals. Examples include bimetallic temperature switches and piezoelectric accelerometers.

Finally, sensors can be classified by how they handle energy. Energy-conversion sensors do not require external power and convert the input energy directly, such as solar cells or piezoelectric devices. Energy-controlled sensors, however, need an external power source to operate, with the input signal modulating the energy flow, as seen in strain gauges and photocells.