Potentiometric metering apparatus

Claim 1

Reference fluid metering apparatus for use with a sample fluid metering device to substantially concurrently deposit a sample fluid onto a first test area and a reference fluid onto a second test area of a generally planar, potentiometric test element supported in a metering station, the reference fluid metering apparatus comprising: (a) reference fluid supply means supported in a location spaced from the metering station; (b) dispensing means including a metering tip angularly arranged for receiving reference fluid located in the supply means and for delivering a predetermined quantity of the reference fluid to the second area of the test element, the dispensing means being selectively movable between a at least a position overlying the supply means and a second position in which the metering tip is positioned over the second test area and closely adjacent the first test area of the test element and disposed at an angle to the sample fluid metering device; (c) drive means for moving the dispensing means between the first and second positions; and (d) logic and control means for automatically controlling the operations of the sample fluid metering device, dispensing means and drive means to effect the delivery of fluids to the first and second test areas at substantially the same time.