 Other pumps which use exactly the same working principle, but using something other than titanium as a source are also relatively common.This family of pumps are usually called 'getter pumps' or 'getters' and typically consist of metals which are reactive with the components of the residual gas which are not pumped by the TSP.By choosing a number of such sources, most constituents of the residual gas, except for the noble gases, can be targeted.