Normally the hydrogen gas is non-toxic. However, you can not deny the fact that it is highly flammable and can ignite at very low temperatures in the presence of flame or spark. So, the estimation of the gas is always important, but it requires a sensor or module. So, from the series of MQ gas sensors, the MQ8 sensor is specifically designed to detect hydrogen gas.
An Overview about MQ8 Sensor
The MQ8 sensor is a simple hydrogen gas sensor, convenient for detecting hydrogen concentrations in the air. Thus, the MQ8 sensor can detect hydrogen gas concentrations anywhere in the range from 100 to 10000ppm. Because of its low cost, and it is suitable for air quality monitoring applications
Internal structure
The MQ8 hydrogen sensor comprises a tin dioxide (SnO2), a perspective layer inside aluminum oxide micro-tubes (measuring electrodes), and a heating element inside a tubular casing. There is an enclosed stainless steel net at the end face of the sensor and the backside holds the connection terminals.
Working Principle
When there is hydrogen gas exists in the surroundings, the conductivity of the sensor gets higher when the concentration of the gas rises. One can convert the change of conductivity to the output signal of gas concentration with the help of a simple circuit using a microcontroller.
Features and Specifications of MQ8 Sensor
There are many prominent features and specification of MQ-7 which makes it more extraordinary
Features
- High sensitivity to Hydrogen (H2)
- Small sensitivity to alcohol, LPG, cooking fumes
- Stable and long life
Specifications
- Operating Voltage: 5V DC
- Detects H2 Gas concentration in air
- Resistant to LPG, smoke, alcohol
- Heater power consumption: < 800mW
- Can detect H2 gas in the concentration range of 100 to 1000ppm
Pinout of MQ8
| Pin Number | Pin Name | Description |
| 1 | Vcc | The [in is there to power the module, requires 5V |
| 2 | Ground | To connect the module to the system’s common ground |
| 3 | Digital Out | Digital output pin, the Threshold value can be set by using the potentiometer |
| 4 | Analog Out | Analog output pin. Analog voltage based on the concentration of the gas |
Applications of MQ8 Sensor
Hydrogen Gas Detector
Through this system, we can immediately collect information on hydrogen gas, and we can also display other gases which can be processed by any microcontroller, and the results on the OLED display, can be used in mines.
Gas Leakage Detecting Systems in Industries
The objective of detecting a gas leak is to prevent the worst potential causes of the hydrogen gas leak, using the above type of MQ sensor. The choice of the MQ-8 sensor is because of MQ-8 which is suitable for detecting natural gas.
