An air quality detection sensor designed to detect harmful gases such as ammonia, nitrogen oxides, alcohol, benzene, smoke, and carbon dioxide. It is widely used in air quality monitoring systems, smart home devices, environmental monitoring, and IoT projects. Compatible with Arduino, ESP32, Raspberry Pi, AVR, and other microcontrollers. Features: Detects multiple harmful gases and smoke Suitable for air quality monitoring Analog and digital output support Adjustable sensitivity via onboard potentiometer Fast response and stable performance Easy integration with microcontrollers Specifications: Sensor Model: MQ-135 Operating Voltage: 5V DC Output Type: Analog and Digital Detectable Gases: Ammonia, NOx, alcohol, benzene, smoke, CO₂ Sensitivity Adjustment: Yes Response Time: Fast response and recovery Application: Air quality monitoring, environmental sensing, smart home systems, industrial monitoring, IoT projects