An automated standards sampling apparatus comprising a connection system for alternately fluidically and electronically coupling either a plurality of standards vials in a vial set assembly or an online flowing liquid sample to a fluid analyzer, wherein the connection system further comprises at least a sample needle and at least a vent needle associated with each standards vial of a vial set assembly, in combination with a computer information reading and control system (16, 71) for operating the connection system so as to deliver either the online liquid sample or a sequence of samples from the standards vials to the analyzer in a predetermined sequence, the automated standards sampling apparatus further comprising: fluid conduits for carrying the online flowing liquid sample or, alternatively, a sample from one of the standards vials to a hub valve and from the hub valve to the analyzer, together with fluid valves operated by the computer control system (16, 71) to control the flow of liquid to the hub valve and to the analyzer; and characterized by a vial set receiving structure configured to receive a standards vial set, the vial set receiving structure comprising a plurality of vial chambers, wherein a spacing between a first vial chamber and a second vial chamber is greater than a spacing between the second and a third vial chamber and also greater than a spacing between the third and a fourth vial chamber, so that the configuration of the vial chambers provides a physical key feature to insure that the vial set is correctly inserted into the vial set receiving structure, such vial set assembly comprising a plurality of individual standards vials and a vial housing for retaining the individual vials in a fixed relationship relative to one another, said vial set assembly also being sized and adapted to mate with the set of needles comprising a needle assembly of said connection system. in combination with a computer information reading and control system (16, 71) for operating the connection system so as to deliver either the online liquid sample or a sequence of samples from the standards vials to the analyzer in a predetermined sequence, the automated standards sampling apparatus further comprising: fluid conduits for carrying the online flowing liquid sample or, alternatively, a sample from one of the standards vials to a hub valve and from the hub valve to the analyzer, together with fluid valves operated by the computer control system (16, 71) to control the flow of liquid to the hub valve and to the analyzer; and characterized by a vial set receiving structure configured to receive a standards vial set, the vial set receiving structure comprising a plurality of vial chambers, wherein a spacing between a first vial chamber and a second vial chamber is greater than a spacing between the second and a third vial chamber and also greater than a spacing between the third and a fourth vial chamber, so that the configuration of the vial chambers provides a physical key feature to insure that the vial set is correctly inserted into the vial set receiving structure, such vial set assembly comprising a plurality of individual standards vials and a vial housing for retaining the individual vials in a fixed relationship relative to one another, said vial set assembly also being sized and adapted to mate with the set of needles comprising a needle assembly of said connection system. fluid conduits for carrying the online flowing liquid sample or, alternatively, a sample from one of the standards vials to a hub valve and from the hub valve to the analyzer, together with fluid valves operated by the computer control system (16, 71) to control the flow of liquid to the hub valve and to the analyzer; and characterized by a vial set receiving structure configured to receive a standards vial set, the vial set receiving structure comprising a plurality of vial chambers, wherein a spacing between a first vial chamber and a second vial chamber is greater than a spacing between the second and a third vial chamber and also greater than a spacing between the third and a fourth vial chamber, so that the configuration of the vial chambers provides a physical key feature to insure that the vial set is correctly inserted into the vial set receiving structure, such vial set assembly comprising a plurality of individual standards vials and a vial housing for retaining the individual vials in a fixed relationship relative to one another, said vial set assembly also being sized and adapted to mate with the set of needles comprising a needle assembly of said connection system.