Blood pressure is usually expressed in terms of the systolic pressure (maximum during one heart beat) pressure over diastolic pressure (minimum in between two heart beats) and is measured in millimeters of mercury (mmHg), above the surrounding atmospheric pressure (considered to be zero for convenience).
Corrosion on the terminals is due to hydrogen gas being released from the acid in the battery. It mixes with other things in the atmosphere under the hood and produces the corrosion you see on the terminals. Generally, if the corrosion is occurring on the negative terminal, your system is probably undercharging.
The maintenance issues which have particularly arisen with aging aircraft structural failure have generally been seen as arising from fatigue or corrosion, with corrosion sometimes initiating fatigue effects. Metallic Corrosion. Metallic Corrosion occurs when chemical action causes deterioration of the surface of a metal. Most corrosion is galvanic or electrolytic in origin, which means that it has occurred because two dissimilar metals have been together in an electrolyte (usually ...