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