Mq 7 Gas Sensor Working Principle

Mq 9 gas sensor module.

Mq 7 gas sensor working principle.

Normally the atmosphere will contain more oxygen than combustible gases. The most commonly used chemiresistor is tin dioxide sno2 which is an n type semiconductor that has free electrons also called as donor. Pnp transistor won t work with a mentioned flying fish module because it has heater pin soldered to sensor s output but can be used with a discrete mq 7 sensor. R and r 0 is the sensor resistances at the steady state and flat band state respectively.

This is a robust gas sensor suitable for sensing lpg smoke alcohol propane hydrogen methane and carbon monoxide concentrations in the air if you are planning on creating an indoor air quality monitoring system. Mq 2 mq 5 aq 2 mq 306a aq 3. Breath checker or early fire detection system mq2 gas sensor module is a great choice. 1 configuration a or b sensor composed by micro al2o3 ceramic tube tin dioxide sno2 sensitive layer measuring electrode and heater are fixed into a crust made by plastic and stainless steel net.

Structure and configuration of mq 7 gas sensor is shown as fig. Here e s is the surface electron concentration of particles and l d is the debye length. The heater provides necessary work conditions for work of sensitive components. The mq 6 sensor module comes with a digital pin which makes this sensor to operate even without a microcontroller and that comes in handy when you are only trying to detect one particular gas.

When sensor materials are selected n d a l d and r 0 are fixed while p is dependent on the actual gaseous conditions. The ability of a gas sensor to detect gases depends on the chemiresister to conduct current. Give your next arduino project a nose for gasses with the mq2 gas sensor module. Sensitive material of mq 9 gas sensor is sno2 which with lower conductivity in clean air.

Where to use mq 6 gas sensor. The mq 6 gas sensor can detect or measure gases like lpg and butane. The heater provides necessary work conditions for work of sensitive components. 3 sensor composed by micro al2o3 ceramic tube tin dioxide sno2 sensitive layer measuring electrode and heater are fixed into a crust made by plastic and stainless steel net.

Structure and configuration of mq 7 gas sensor is shown as fig. The mq 7 is a carbon monoxide co sensor suitable for sensing co concentrations in the air. The sensor s conductivity is more higher along with the gas concentration rising. Mq 7 gas sensor brand.

For other symbols see the caption of fig 1. As described above mos type gas sensors change.