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.
exists and is an alternate of . Corrosion at Battery Terminals Usually, battery terminal corrosion occurs when the factory seal between the battery case and the lead terminal has failed, allowing some electrolyte [battery acid] to work its way through to the outside. It tends to wick upward [due to surface tension] on the terminal post, and eventually to the cable clamp also.