High purity helium means that its composition is more than 99.999%, which means that the impurity content is less than 10% of the gas * 10-6 (volume fraction). The total impurities in the pure gas supplied by industry are usually less than 100 * 10-6 (volume fraction), so the impurities must be removed to 10% * 10-6 or lower by further purification.

Deoxygenate

Chemical methods are usually used to remove oxygen. Common deoxidizers include manganese oxide or Ag-X molecular sieve. Manganese oxide deoxidizer absorbs oxygen. The total reaction is 2MnO+O2—2MnO2. At a reaction temperature of 150 Celsius degree and an airspeed of 1000h-1, 0.1% (volume share) of oxygen can be removed to 2 * 10-6 (volume share). Ag-X molecular sieve was used for deoxidation at room temperature. Impurity oxygen content can be measured between 44*10-6 and 3*10-6. Manganese oxide and Ag-X molecular sieve deoxidizer must be reduced with hydrogen after use, reduced deoxidizer can be reused.