20pcs MQ-4B Sensor Gas Sensor CO CO2 Smoke Methane Sensor Detecting MQ Sensor DIY for Safety Detection System

 Overview   The gas sensing material used in the MQ 4B methane sensor is tin dioxide SnO2 with lower conductivity in clean When there is a flammable gas in the environment where the sensor is located the conductivity of the sensor increases as the concentration of flammable gas in the increases The change in conductivity can be converted to an output signal corresponding to the gas concentration using a simple circuit The MQ 4B methane sensor has high sensitivity to methane and strong anti interference ability to alcohol and other disturbing gases Characteristics This product has good sensitivity to methane in a wide concentration and has the advantages of long life low cost and simple driving circuit Application Widely used in household gas leak alarms industrial combustible gas alarms and portable gas detectors Basic Circuit The figure above shows the basic test circuit for the MQ 4B sensor The sensor requires two voltages to be applied voltage VH and test voltage VC The VH is used to provide a specific operating temperature for the sensor either DC or AC The VRL is the voltage across the load resistor RL of the sensor in series VC is the voltage for testing the load resistor RL and requires a DC power supply   Package Included  20 x MQ 4B Sensor Gas Sensor CO CO2 Smoke Methane Sensor