Method and a device for monitoring a medical microsample in the flow measuring cell of an analyzer

A device for monitoring a microsample in a flow measuring cell of an analyzer comprising:

• at least one electrode system comprising at least two single electrodes positioned within said flow measuring cell, wherein
• said electrode system is configured for measurement of at least one substance contained in the microsample by application of a measurement voltage which is essentially a DC voltage, and detection of absence of bubbles and/or positioning of said microsample by application of an alternating voltage to said flow measuring cell,
• both the alternating voltage and the measurement voltage are simultaneously and directly applied to the single electrodes of the respective electrode system, and
• the measured AC component or the measured impedance provides a measure for the position of the microsample and/or the absence of bubbles;
• and
• a circuit for producing the voltages to be applied to the single electrodes, which circuit has a summation point at which the alternating voltage for the purpose of monitoring the microsample with regard to position and/or absence of bubbles is superposed on the DC voltage serving as measurement voltage.