A biosensing meter (50) receives a biomedical sample strip (10) which includes electrically isolated excitation (14) and sense (12) electrodes or, alternatively, a check strip. The biosensing meter includes first and second contacts (C, D) that are connected by a sense electrode upon insertion of a sample strip. An operational amplifier circuit has first and second inputs respectively connected to the first contact and a reference potential, the first input manifesting the reference potential as a result of a feedback within the operational amplifier. A processor (60) is coupled to the second contact and determines the presence of the reference potential at the second contact when an inserted sense electrode connects the first and second contacts. The processor also distinguishes between sample and check strips and tests for a proper impedance between the sense and excitation electrodes of a sample strip, thus enabling operation of the biosensing meter upon sample strip dosing.