Trace Oxygen Analyzer Installation
Teledyne Analytical Instruments 7
between a battery and a true fuel cell. (All of the reactants are stored
externally in a true fuel cell.)
2.2.2 Anatomy of a Micro-fuel Cell
The Micro-fuel Cell is made of extremely inert plastic (which can
be placed confidently in practically any environment or sample stream).
It is effectively sealed, though one end is a gas permeable membrane.
At the permeable end a screen retains a diffusion membrane through
which the oxygen passes into the cell. At the other end of the cell is a
printed circuit board with concentric gold contacts.
Refer to Figure 2-1, Cross Section of a Micro-fuel Cell, which
illustrates the following internal description.
Figure 2-1: Cross Section of a Micro-fuel Cell
At the sensing end of the cell is a diffusion membrane, whose
thickness is very accurately controlled. Near the diffusion membrane lies
the oxygen sensing element—the cathode.
The anode structure is larger than the cathode. It is made of lead
and is designed to maximize the amount of metal available for chemical
reaction.
The space between the active elements is filled by a structure
saturated with electrolyte. Cathode and anode are wet by this common
pool. They each have a conductor connecting them, through some