2pcs MQ 3 Alcohol Gas Sensor Module Ethanol Detector Breath Gas Detection Board

Features: 1. Using double sided circuit board design, with power indicator and TTL signal output indicator. 2. With DO switching signal (TTL) output and analog output AO. 3. TTL output valid signal is low level. (When the output is low level, the signal light is on, it can be directly connected to the MCU or relay module) 4. Analog output voltage, the higher the voltage, the higher the concentration. 5. High sensitivity for the detection of alcohol gas. 6. Rapid response and recovery characteristics. 7. There are four screw holes for easy positioning Detailed Test Parameters: Model: MQ 3 Detecting gas: alcohol vapor Detection concentration: 0.04 4mg L alcohol Standard circuit condition: Loop voltage VC less than 24DC Heating voltage :VH 5.0+ 0.2V AC DC Load resistance: RL adjustable Gas sensor characteristics under standard test condition: Heating resistor 31 Ohm + 3 Ohm Heating power consumption: less than 90mW Sensitive surface resistance: 2K Ohm 20K Ohm (in 0.4mg L alcohol) Sensitivity: Rs (in air) Rs (0.4mg L alcohol) more than 5 Concentration slope: less than 0.6 (R300ppm R100ppm alcohol) Standard test conditions: 20 celsius + 2 celsius ; 65percent + 5percent RH Standard test circuit: 5.0V + 0.1V Warm up time: more than 48 hours Electrical Properties: Input voltage: DC5V Power consumption (current ): 150mA DO output: TTL digital 0 and 1 ( 0.1 and 3.3V) AO output: 0.1 0 .3V, the highest concentration voltage is about 4V 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: 1. VCC: connected to the positive pole of the power supply 2. GND: connected to the negative power supply 3. DO: TTL switching signal output 4. AO: analog signal output Package list: 2 x Alcohol Gas Sensor