Parts per Million vs Percentage of Oxygen

Oxygen Percentage   Parts Per Million
100% = 1,000,000 (One million ppm)
    10% = 100,000 (One hundred thousand ppm)
1% = 10,000 (Ten thousand ppm)
0.1% = 1,000 (One thousand ppm) good level for Weld Purging of duplex and stainless steels
0.01% = 100 (One hundred ppm)
0.001% = 10 (Ten ppm) suitable level for welding titanium and UHP joints in stainless
0.0001% = 1 (1 ppm)

This chart is simply provided to help explain the relationship between parts per million and percentage of oxygen.

Download Parts Per Million Reference Sheet

Download Detailed Parts Per Million Reference Sheet

Download The Earth’s Atmosphere in PPM