Advantages and disadvantages of human body sensor

　　Pyroelectric materials used for infrared detection of human body are cheap, do not emit any beam, and have very low power consumption, so they are widely used. But from the principle, it can be seen that this kind of human body sensor can only sense the movement of the human body, that is, the change of the infrared emitted by the human body. If the human body is still, the sensor cannot distinguish. Of course, it is impossible for a normal human body to be absolutely still. To be exact, the range of human body movement is greater than the "blind area" and "high sensitivity area" generated by Fresnel lens. Therefore, it is obvious that the closer the human body sensor is, the stronger the human body sensor's ability to distinguish weak human actions. In addition, for the human body sensor, it detects the infrared changes caused by human body movement, and objects or creatures close to the human body temperature, such as cats, dogs and other pets, radiators, lights, etc., can also trigger the human body sensor by mistake. If the infrared ray emitted by the human body is blocked by glass, shower curtain and other materials, or the ambient temperature is very close to the human body temperature, the human body sensor may still fail to detect the human body.

　　Although transparent materials such as glass do not seem to attenuate visible light, they may still attenuate the infrared ray emitted by the human body, so the surface of the human body sensor, that is, the side with Fresnel lens, cannot be shielded by materials such as glass. Moreover, the sensing range of human body sensor is relatively large, and it is not suitable to be installed inside 86 cassettes, etc., so the concealment of human body sensor in actual installation and use is a problem: it highlights that it is easy to affect the beauty, and concealment also affects the function. Therefore, the human body sensor with the smallest volume or the human body sensor with the color similar to the indoor style should be selected as far as possible in use to find a balance between beauty and practicality.

Read recommendations:

Electronic thermometer NTC thermistor resistance.Human Body Infrared Temperature Sensor Vendor

Why can radio frequency level gauges be widely used?

PND103F3950FTR325

PIR Lens 8731-1

PIR Lens 8140