A volume adjustable pipette, comprising a plunger mounted for movement in a housing to and from a stop to aspirate a fluid into and dispense the fluid from a tip extending from the housing. The ion source material may include at least one of a chalcogenide material and a metal. An end of the press handle has a round projection with an eccentric pivotal hole. When the carriage is engaged with the reel spool, a pair of curved tracks are positioned so that arcs defined by the tracks have their centers coincident with the spool axis. The proof may include a digital signature of the time interval and the data.