Patent ID: 8828320

Claim:
A sample analyzer comprising: a housing; a cartridge disposed within and removable from the housing, the cartridge comprising: at least one flow channel comprising at least a first wall, a second wall, and a volume within the channel, wherein the second wall is positioned opposite to and spaced a distance from the first channel wall; and a first electrode situated on the first wall and extending into the at least one flow channel such that the first electrode is in contact with a fluid flowing through the at least one flow channel; and a second electrode situated on the second wall and extending into the at least one flow channel such that the second electrode is in contact with the fluid flowing through the at least one flow channel; and a signal source connected to the first electrode and the second electrode, the signal source in combination with the first and second electrodes capable of measuring voltage and current characteristics of a signal across the at least one flow channel; and a controller disposed within the housing and configured to receive an output signal from the signal source in combination with the first and second electrodes, the output signal indicative of a voltage and current characteristic of the signal across the at least one flow channel, the controller providing no result, an error message or an error code when the voltage and current characteristic measured by the first and second electrodes and the signal source is outside of a certain range for the fluid.