MQ303A

MQ303A Alcohol Sensor Character * High sensitivity * Fast response and resume * Long life and low cost * Mini Size Application MQ303A is semiconductor sensor is for Alcohol detection, It has good sensitivity and fast response to alcohol, suitable for portable alcohol detector. Configuration Technical Data Model No. MQ303A Sensor Type Semiconductor Standard Encapsulation Metal Detection Gas Alcohol Concentration 20-1000ppm Alcohol Heater Voltage V H Loop Voltage Vc 0.9V ± 0.1V AC or DC ≤6V DC Standard Circuit Conditions Load RL Resistance Heater Resistance RH Adjustable 4.5Ω ± 0.5 Ω（Room Tem.） Heater Current Heater Power Sensor Consumption IH PH PS 120±20mA ≤ 140 mW ≤10 mW Character Sensing Resistance Rs 4KΩ-400KΩ(in air) Sensitivity S Rs(in air)/Rs(125ppm Alcohol)≥3 Slope α 0.50 ± 0.15(R300ppm/R100ppm Alcohol) Tem. Humidity 20℃±2℃；65%±5%RH Condition Standard test circuit Vc:3.0 V±0.1 V DC ； VH: 0.9 V±0.1 V DC Preheat time Over 48 hours Sensing element of the semiconductor sensor is a micro-ball, heater and metal electrode are inside, and the sensing element is installed in anti-explosion double 100 mesh metal case (see the above) Sensitivity Characteristics Influence of Temperature/Humidity Fig.2 is the test circuit. You could get resistance change from voltage change on fixed or adjustable load resistance. Normally, it will take several minutes preheating for sensor enter into stable working after electrified; oryou could give 2.2±0.2V...