Different technical principles of smart home body sensor finished products

Different technical principles of smart home body sensor finished products, with the popularization of smart home, more and more people use smart home. To make our daily life more comfortable and convenient, smart homes are becoming smarter. In order to achieve a more intelligent effect, various sensors are essential.

In our family life, people are the most important, so the importance of finished body sensors is self-evident. At present, in the smart home industry, there are mainly the following types of human sensors. Let's introduce them separately.

1. Finished products of Doppler micro-radar sensing human body sensor

The common frequency band is 5.8GHz.24GHz. The principle is the Doppler principle. If a moving object enters the sensing range, the radar signal waveform will change, thereby triggering the movement of the radar sensor. Using the Doppler principle, it can detect human motion and fretting, and detect human breathing and thoracic activity. Penetrating plastic shell, concealed installation, more beautiful, it can detect moving human body or stationary or sleeping person.

2. Infrared sensor

Using the principle of pyroelectric infrared sensing, the sensor is triggered to work by collecting changes in infrared energy. Affected by the ambient temperature, when the ambient temperature in summer is close to the human body temperature, there is no change in infrared energy when people enter the sensing range, so the human body induction switch is not very sensitive in summer. Advantages: low price, mature product. Disadvantages: It is greatly affected by the ambient temperature, the infrared probe needs to be exposed, and the overall aesthetics of the product is not high.

At present, the development of finished smart home body sensors is very mature, but with the diversification of smart home scenarios, consumers have put forward more diverse needs for high-precision body sensors. This requires us to match different human sensing technologies when designing smart home products to meet the needs of consumers.

A gas detector is a device that detects the concentration of various gases. Generally, the gas sensor is the core, and various signals output by the sensor are converted into identifiable electrical signals through advanced technical means, and the test results are displayed to achieve the exploration effect. Alarm modules can also be equipped to maximize control over the scenarios involved in each category. Three gases can be said to be the main application areas of gas detectors: flammable gases, toxic gases and oxygen.

1. Combustible gas

Flammable gases such as methane, butane, propane, etc. Combustion of relevant gases has three prerequisites. In addition to combustible gases, oxygen and an ignition source are also required. In other words, without one of these three premises, no combustion or explosion can occur. Flammable gas detection should refer to the important limit - lower explosion limit. In other words, if the concentration of flammable gases in the air exceeds the lower explosive limit, combustion and explosion will occur. Generally, the alarm or alarm value of a gas detector is set at less than half of the lower explosion limit to provide a safety limit for first aid.

2. Toxic gas

Carbon monoxide, carbon dioxide, hydrogen, chlorine, etc. are all toxic gases. Even if the concentration of some toxic gases is low, they will cause great harm to the human body. Therefore, there are also associated restrictions on toxic gases. All countries have corresponding standard restrictions. In addition, exposure time is also one of the key factors in the detection of toxic gases. In the case of carbon monoxide, 20 minutes of exposure is acceptable if the concentration remains around 1000ppm, but discomfort occurs if it exceeds 20 minutes. The exposure time exceeds 40 minutes, and the safety of life is threatened.

3. Oxygen

There are two concepts of oxygen check: hypoxia and oxygen enrichment. Of course, the risk of hypoxia is that if the oxygen content in the air drops below 19.5% v/v, symptoms such as a hypoxic environment, dizziness, headache, palpitations, and difficulty breathing will appear. When the oxygen content in the air drops below 16% v/v, the breathing environment is very harsh. Plenty of oxygen is also dangerous. When the oxygen content in the air rises above 24% v/v, some items will spontaneously ignite, and the flammability of materials and gases will also be relatively improved.

Therefore, the application of gas detectors in petroleum, petrochemical, power generation, semiconductor manufacturing, tunnels, parking lots, hospitals and other fields is particularly important. The choice of gas detector depends on the inspection environment, inspection principle, limitations, sampling method, range, accuracy, and protection level. The shell material has deep doorways. Appropriate instruments and equipment, cost-effectiveness, service life, and maintenance guarantee should be selected, or a professional sensor manufacturer should be consulted to consider sensor products with brand influence.