An electrical system for measuring a parameter of a liquid sample such as the hematocrit and an approximation of hemoglobin for a blood sample. The system basically comprises an instrument and a disposable sample card. The instrument is a hand-held, battery-operated device used for the fast and simple measurement of a parameter such as blood conductivity. The instrument accepts the disposable sample card, which is used for the one-time conveyance and application of a liquid sample, such as blood, to the instrument. The instrument has provision for digital displays for read-outs. There are no external switches on the instrument, and power is automatically applied when the disposable sample card is inserted into the instrument.
The instrument basically comprises an electronic portion for processing data obtained from the liquid sample on the sample card, a front-end mechanism for positioning the sample card within the instrument, and a digital display for displaying in eye-readable form the results of a parameter measurement made in the instrument.