Pir Sensor Adopts Digital Fuzzy Logic Infrared Control System and Intelligent Analysis Algorithm. It Can Tell the Interference Signal and Human Movement Signal to Avoid Fault Alarm. Also It Has Temperature Compensation and Air Flow Technology to Get Used to the Change of the Environment. The Device Has the Features of Environmental-friendly, Safety and Easy Installation. It Can Reflect the Low Voltage Automatically to Help the Gsm Alarm to Send Low Voltage Message to Users. The Product Is Suitable for Housing Estate, Villa, Factory, Warehouse, Office Building and So on.