The initial demand for electrical equipment to prevent explosion came from the coal mine, because there was gas under the coal mine, which was very easy to cause explosion or combustion.  With the development of industrialization, people's demand for explosion-proof electrical equipment has expanded to various fields-petroleum, chemical industry, medicine, navigation, aerospace, metallurgy, scientific research and military industry, etc.  The demand is even greater, with different requirements and stronger pertinence. Especially, the rapid development of China's petrochemical industry has accelerated the development of explosion-proof industrial monitoring products, and a large number of electrical equipment have been used in production.  The electrical equipment, safety equipment and lighting fixtures used also inevitably produce electric sparks, electric arcs and high temperatures allowed under normal circumstances. However, due to factors such as site conditions, the concentration of explosive hazardous mixture may continuously increase. When reaching a certain concentration, the detonated source-electric sparks, electric arcs and high temperatures will detonate, with unimaginable consequences.  In recent years, there have been many explosion accidents. The more serious ones are: (August 12, 2015) the explosion accident in Tianjin Binhai New Area, (August 2, 2016) the explosion accident in Kunshan factory in Jiangsu Province, (April 12, 2017) the explosion accident in Chongqing oil storage tank, (December 10, 2017) the explosion in Lianyungang chemical enterprise workshop in Jiangsu Province, etc.  In the process of experiment, production, processing, transportation and storage, many industrial enterprises or research departments, such as petroleum, chemical industry, gunpowder and natural gas, often leak and spill out various flammable and explosive gases, liquids, various dust and fibers. When mixed with air, these substances will become mixtures prone to explosion hazards, and the places around them will also become explosion hazardous places to varying degrees.  When the concentration of explosive reaches the critical point of explosion, serious accidents such as explosion and fire will occur once the explosive source appears, causing casualties and property losses.  Therefore, cameras, electric tripod heads, junction boxes and other equipment installed in hazardous areas used in these places must be explosion-proof.  The electrical explosion-proof type can be divided into explosion-proof type, intrinsically safe type, pouring and sealing type, etc.  At present, explosion-proof cameras on the market mostly adopt explosion-proof type, and explosion-proof is the most direct and economical explosion-proof type.  Explosion-proof cameras, explosion-proof high-speed balls, explosion-proof junction boxes and other explosion-proof monitoring equipment produced by Shenzhen Rongfang Company also adopt explosion-proof structures.  So is it necessary to use explosion-proof equipment in all sectors of the above-mentioned industries?  The answer is no.  Front-end equipment requires high-level explosion-proof equipment to ensure maximum safety.  What are the front-end devices?  For example, explosion-proof cameras, explosion-proof ball machines, explosion-proof junction boxes and other equipment must be installed at the scene, which belongs to the front-end equipment.  The monitoring room can be located in a safe area, so the equipment in the monitoring room can be conventional equipment, which can effectively reduce the cost.