Platinum Electrodes: A very thin porous platinum (Pt) layer is coated on the inner and outer surfaces of the zirconia element to serve as electrodes. Inner electrode: Exposed to the reference gas (usually dry, clean air containing 20.95% O2). Air diffuses naturally into the inner reference gas chamber through the calibrated hole. Sit up straight, seek truth, and be sincere.

· Daily Motto: You can, you should, and if you're brave, you will.