Get the PPM values from the MQ Gas sensors

Job ID: 34106646

Budget: $10 – $30 USD

I'm using two types of gas sensors (MQ-9 - Carbon Monoxide and MQ136 - Hydrogen Sulfide ) with Arduino. the code works fine but the values are very high and i think there is a formula to get the PPM values from both sensors. I need to get the correct PPM values.