1-10pcs New MQ135 MQ-135 Air Quality Sensor Hazardous Gas Detection Module For Arduino M2 PromotionHot New Arrival modname=ckeditor New MQ135 MQ-135 Air Quality Sensor Hazardous Gas Detection Module for Arduino M2 PromotionHot New Arrival Product Overview: MQ135 gas sensor sensitive material used in the clean air, low conductivity tin oxide (SnO2). When present in the environment pollution gas sensor, conductivity sensor with the increase in air pollution in the gas concentration increases. Use simple circuit can convert the change in conductivity of the gas concentration corresponding to the output signal. MQ135 ammonia gas sensor, sulfide, benzene vapor high sensitivity, smoke and other harmful monitoring will also be ideal. The sensor can detect a variety of harmful gases, it is a low-cost sensors for a variety of applications. Application: Can be used for home and factory gas leakage monitoring devices, suitable for liquefied petroleum gas, butane, propane, methane, smoke, etc. Features: Using high-quality dual-panel design,with power indicator and TTL signal output instructions. The switching signal having a DO (TTL) output and analog output AO. TTL output valid signal is low. ( Low-level signal when the output light can be directly connected to the microcontroller or relay module ) Analog output voltage with the higher concentration of higher voltage There are four screw holes for easy positioning. Has a long life and reliable stability Rapid response and recovery characteristic Input voltage : DC5V Power consumption ( current ): 150mA DO output : TTL digital 0 and 1 ( 0.1 and 5V) AO output :0.1-0 .3 V ( relative to pollution ),the maximum concentration of a voltage of about 4V Special note: After the sensor is powered,needs to warm up around 20S,measured data was stable,heat sensor is a normal phenomenon,because the internal heating wire,if hot is not normal . Wiring: VCC: positive power supply (5V) GND: power supply is negative DO: TTL switching signal output AO: analog signal output NOTE: After the sensor is powered, need to warm about 20S, measured data becomes stable, heat sensor is normal _x000D_