a device which indicates fluid pressure by liquid levels usually employing a U tube filled with mercury or water. The level of the liquid above or below a reference point indicates the fluid pressure relative to ambient pressure. Unless otherwise specified, it indicates the fluid pressure relative to ambient atmospheric pressure.
"Source data" means those data, recorded during measurement or calibration or used to derive empirical relationships, which identify nuclear material and provide batch data. Source data may include, for example, weight of compounds, conversion factors to determine weight of element, specific gravity, element concentration, isotopic ratios, relationship between volume and manometer readings and relationship between plutonium produced and power generated.
