A compliant contact pin assembly and a contactor card system are provided. A penetrating member driver is coupled to the plurality of penetrating members. The electrochemical gas sensor further includes a passage in the surface for holding or transporting gas received from a gas source, whereby sensing occurs at a three way interface where the gas, electrolytic material, and electrodes come in direct contact with one another. A half-width of the highest intensity peak falls within a range of 0.