 An alternative approach involving controlled pumping of the main chamber may not solve the problem entirely either because the 100% relative humidity cannot be approached monotonically without any drying, or the process is very slow; inclusion of a water reservoir inside the main chamber means that one cannot lower the relative humidity until after all of the water is pumped out (i.e.a defective control of the relative humidity).During the interaction of an electron beam with a specimen, changes to the specimen at varying degrees are almost inevitable.