A biomedical sensor system is disclosed that includes a plurality of electrodes and a contiguous adhesive material that is in contact with each of the plurality of electrodes. The negative resistance generation block generates a negative resistance in response to the minute variations of an output voltage. Information about a client application may be applied to each new session to create permanence or apparent permanence for the user from session to session. A method of aligning an underground structure is also disclosed. The device is airtight and used to detect oxygen-sensitive species, such as dithionite in groundwater following a remedial injection to treat soil contamination.