The working principle of the sensor for the limit protector HQQ-8967XC of the Qinghai Zhuoxin brand coal feeder is that the sensor is a detection device that can sense the measured information and transform it into a signal or the required form of information output according to certain rules, in order to meet the requirements of information transmission, processing, storage, display, recording, and control. The characteristics of the HQQ-8967XC coal feeder limit protection sensor include miniaturization, digitization, intelligence, multifunctionality, systematization, and networking. It is an essential part of achieving automatic detection and control. The existence and development of sensors have provided objects with senses such as touch, taste, and smell, making them gradually come to life. Usually, it is divided into categories based on its basic perceptual function, including thermal sensors, components, gas sensors, force sensors, magnetic sensors, humidity sensors, sound sensors, radiation sensors, color sensors, and taste sensors. In basic disciplines, sensors have a more prominent position in product descriptions. The development of modern science and technology has entered many new fields: for example, at the macro level, we need to observe the vast universe spanning thousands of light-years, at the micro level, we need to observe particles as small as fm, vertically, we need to observe the evolution of celestial bodies that last for hundreds of thousands of years, and in the short term, instantaneous reactions. In addition, various technologies have emerged that play an important role in deepening material understanding, exploring new energy, new materials, etc., such as overheating, overheating, overpressure, ultra vacuum, * magnetic field, ultra weak magnetic field, etc. Obviously, it is impossible to obtain a large amount of information that cannot be directly obtained by human senses without appropriate sensors. Many obstacles in basic science first lie in the difficulty of obtaining object information, and the emergence of new mechanisms and sensitivity detection sensors often leads to breakthroughs in this field. The development of some sensors is often developed by some interdisciplinary fields. Ningxia Zhuoxin brand coal feeder limit protector HQQ-8967XC magnetic switch WEF-QG-1001 magnetic switch FA4-701KL DC 24V two wire normally open proximity switch Re-S1P2J4 M12 PNP normally open buried plug-in C24V photoelectric switch FA3-805PKH-E DC 24V PnP open+close opposed proximity switch FA7-750PK M18, PNP normally open, buried, plug-in, C24VLJKE-S18-320-08T proximity switch LJKE-S30-320-15T proximity switch proximity switch SJM12A3-10J/K3 proximity switch NI 3-EG08-AN6X 24VC proximity switch LJM18A-8Z/KS 24VCLR30BF15N0-E2 proximity switch 220V; Bidirectional; Manual reset stainless steel drawstring switch material 304; Model HQLS-LXB-T1 Bidirectional Rope Switch