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MQ3:

Used for post-drink supervision and detection of motor vehicles and other risky workers and detection of ethanol vapor in other places.

Specification:

Gas: Alcohol (ethanol)
Detection range: 10 ~ 1000ppm alcohol
Characteristic gas: 125ppm alcohol
Sensitivity: R in air/Rin typical gas≥5
Sensitive body resistance: 1 ~ 20KΩ in air
Response time ≤ 10s (70% Response)
Recovery time ≤ 30s (70% Response)
Heating resistance: 31Ω±3Ω
Heating current ≤180mA
Heating voltage: 5.0V ± 0.2V
Heating power ≤900mW
Measuring voltage ≤24V

MQ-3 Module

Product characteristics:

The gas sensing material used in MQ-3 gas sensor is tin dioxide (SnO2) with low conductivity in clean air. When there is alcohol vapor in the environment where the sensor is located, the conductivity of the sensor increases with the increase of combustible gas concentration in the air. With different resistance values for different concentrations, the change of conductivity can be converted into the output signal corresponding to the gas concentration by using a simple circuit. It can resist the interference of gasoline, smoke and water vapor. The sensor can detect alcohol atmosphere of various concentrations, and is a low-cost sensor suitable for various applications. The sensor is equipped with an M3 fixed mounting hole, and a wide voltage LM393 comparator is used. The signal is clean, the waveform is good, and the driving ability is strong, exceeding 15mA. It is equipped with an adjustable precision potentiometer to adjust the sensitivity.

Product parameters:

Working voltage: 5VDC

Power consumption (current): 150mA

Output form: analog and digital output

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

MQ-3B

The gas sensor used in MQ-3B gas sensor is tin dioxide with low conductivity in clean air. When there is alcohol vapor in the environment where the sensor is located, the conductivity of the sensor increases with the increase in the concentration of air alcohol vapor, Use a simple circuit to convert the change of conductivity into an output signal corresponding to the gas concentration.

MQ-3B gas sensor has high sensitivity to alcohol and can resist the interference of gasoline, smoke and water vapor. This sensor can detect alcohol atmospheres of various concentrations and is a low-cost transmitter suitable for various applications.

Product Model: MQ-3B Alcohol Sensor

Product Type: Semiconductor Gas Sensor

Detection gas: alcohol vapor

Detection concentration: 25～500ppm alcohol

Standard circuit conditions: Loop voltage: Vc ≤24V DC

Heating voltage: VH: 5.0V±0.1V AC or DC

Load Resistance: RL: Adjustable

Heating resistance: RH: 9±3Ω (room temperature)

Heating power consumption: PH: ≤900mW

Output voltage: Vs: 2.5V-4.0V (in 125ppm alcohol)

Sensitivity: S: Ro(in air)/Rs(125ppm alcohol)≥5

Concentration slope: α: ≤ 0.6 (R300ppm/R50ppm alcohol)