Although the wire and cable industry is only a supporting industry, it accounts for a quarter of the output value of the Chinese electrical industry. It has a wide range of products and a wide range of applications, involving electric power, construction, communications, manufacturing and other industries, and is closely related to various sectors of the national economy. Wire and cable are also known as the "arteries" and "nerves" of the national economy. They are the basic equipment that can transport electric energy, transmit information and manufacture various motors, instruments and meters, and realize electromagnetic energy conversion. It is the future electrification and information. The necessary basic products in a society. The wire and cable industry is the second largest industry in China after the automotive industry, with product product satisfaction rates and domestic market share exceeding 90%. In the world, the total output value of China's wire and cable has surpassed that of the United States, becoming the world's largest wire and cable producer. Along with the rapid development of China's wire and cable industry, the number of new enterprises has been rising, and the overall technical level of the industry has been greatly improved. From January to November 2007, China's wire and cable manufacturing industry realized a total industrial output value of 476,742,526,000 yuan, an increase of 34.64% over the same period of the previous year; realized cumulative product sales income of 457,503,436,000 yuan, an increase of 33.70% over the same period of the previous year; The total profit was 18,808,301 thousand yuan, an increase of 32.31% over the same period of the previous year. From January to May 2008, China's wire and cable manufacturing industry achieved a cumulative total industrial output value of 241,435,450,000 yuan, an increase of 26.47% over the same period of the previous year; realized cumulative product sales income of 227,131,384,000 yuan, an increase of 26.26% over the same period of the previous year; 8,519,637,000 yuan, an increase of 26.55% over the same period of the previous year. The sustained and rapid growth of China's economy has provided huge market space for cable products. The strong temptation of the Chinese market has made the world focus on the Chinese market. In the short period of reform and opening up, China's cable manufacturing industry The huge production capacity that has been formed has made the world look impressive. With the continuous expansion of China's power industry, data communication industry, urban rail transit industry, automobile industry and shipbuilding industry, the demand for wire and cable will also grow rapidly. In the future, the wire and cable industry has great potential for development. Concerned about surprises Label: History and development of wire and cable Previous: The generation, separation and dust removal technology of the rotary vane oil mist Next: Analyze the vertical steel plate clearing line It is mainly made of a material with high pyroelectric coefficient, such as lead zirconate titanate ceramics, lithium tantalate, triglyceride titanium sulfate, etc. to make the detection element with a size of 2*1mm. Install one or two detection elements in each detector, and connect the two detection elements in series with reverse polarity to suppress the interference caused by the rise of their own temperature. The detection element converts the detected and received infrared radiation into a weak voltage signal, which is amplified by the field effect tube installed in the probe and output outward. In order to improve the detection sensitivity of the detector and increase the detection distance, a Fresnel lens is generally installed in front of the detector. The lens is made of transparent plastic. The upper and lower parts of the lens are divided into several equal parts. It is a kind of lens with a special optical system. It can amplify the signal by more than 70 decibels in cooperation with the amplifying circuit, so that the movement of people within 20 meters can be measured. PassiveInfrared Ray,Pyroelectric sensor,Highly sensitive sensor Dongguan XINYUDA Technology Co., Ltd. , https://www.gdxige.com
The Fresnel lens uses the special optical principle of the lens to produce an alternating "blind zone" and "high-sensitivity zone" in front of the detector to improve its detection and reception sensitivity. When someone walks in front of the lens, the infrared rays emitted by the human body will alternate from the "blind area" to the "high sensitive area", so that the received infrared signal is input in the form of sudden strong and weak pulses, thereby strengthening its energy amplitude .
The central wavelength of infrared radiation radiated by the human body is 9~10--um, and the wavelength sensitivity of the detection element is almost stable in the range of 0.2~20--um. A window equipped with a filter lens is opened at the top of the sensor. The wavelength range of light that this filter can pass is 7~10--um, which is suitable for the detection of human infrared radiation, and other wavelengths of infrared rays are filtered. The sheet is absorbed, thus forming an infrared sensor specially used to detect human body radiation.