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Crowtail- Gas Sensor(MQ3)


The Crowtail - Gas Sensor module is useful for gas leakage detecting(in home and industry). It can detect LPG, i-butane, methane, alcohol, Hydrogen, smoke and so on. Measurements can be taken as soon as possible based on its fast response time. Also the sensitivity can be adjusted by the potentiometer.
The module contains a MQ-3 Gas Sensor and ETA1036. High sensitivity to alcohol and small sensitivity to benzine with a stable and long worklife are most important reasons to choose the MQ-3. The ETA1036 is a high efficiency synchronous step-up converter that can provide up to 3W of power to a boosted output from a low voltage source. The start-up voltage requires only 0.85v and the efficiency up to 96%. The MQ-3 is useful for alcohol detecting. There are different gas detectors for sale, like MQ2, MQ5 and MQ9. Below is a contrast table of them.

Each Crowtail - Gas Sensor Kit consists of one gas sensor base and four detectors. You can switch the detector on the base according to specific target gases.

  • Crowtail - Gas Sensor(MQ2):Combustible Gas, Smoke
  • Crowtail - Gas Sensor(MQ3):Alcohol Vapor
  • Crowtail - Gas Sensor(MQ5):LPG, Natural Gas, Town Gas
  • Crowtail - Gas Sensor(MQ9):Carbon Monoxide, Coal Gas, Liquefied Gas

Model: CT0041GST

Crowtail-Gas Sensor.JPG


  • Work Voltage: 3.3V ~ 5V
  • High sensitivity to Combustible gas in wide range
  • Stable performance, long life, low cost
  • Simple drive circuit
  • Wide detection range
  • Compatible with Crowtail interface
  • Dimensions(mm):40.0(L)x20.0(W)x21.5(H)


Connect the module with Crowtail base Shield using A0 like following picture and use the program below to gain the voltage. The higher the concentration of the gas is, the bigger the output voltage of the SIG pin gets. Sensitivity can be regulated by rotating the potentiometer. Please note that the best preheat time of the sensor is about 24 hours. For the detailed information about the sensor, please refer to the datasheet.