ISO 11223:2004 石油および液体石油製品—直接静的測定—静水圧タンクゲージによる垂直貯蔵タンクの含有量の測定 | ページ 6

3.1

ambient air density

density of ambient air at the tank side on which the pressure sensors are mounted

3.2

ambient air temperature

representative temperature of the ambient air at the tank side on which the HTG pressure sensors are mounted

3.3

apparent mass in air

value obtained by weighing in air against standard masses without making correction for the effect of air buoyancy on either the standard masses or the object weighed

[SOURCE:ISO 3838]

3.4

capacity table

table, often referred to as a tank table or a tank calibration table, showing the capacities of, or volumes in a tank corresponding to various liquid levels measured from a stable reference point

[SOURCE:ISO 7507-1]

3.5

critical zone height

upper limit of the critical zone; the level at which one or more of the floating-roof or floating-blanket legs first touch the tank bottom

3.6

critical zone

level range through which the floating roof or floating blanket is partially supported by its legs

3.7

density

mass of the substance divided by its volume

[SOURCE:ISO 3838]

Note 1 to entry: When reporting the density, it is necessary to explicitly state the unit of density used, together with the temperature. The standard reference temperature for international trade in petroleum and its products is 15 °C (see ISO 5024). Other reference temperatures might be required for legal metrology or other special purposes (see ISO 3993).

3.8

dip

innage

depth of a liquid in a tank

[SOURCE:adapted from ISO 7507-1]

3.9

dipped volume

observed volume of product, sediment and water, calculated from the dip level and the tank capacity table

3.10

fixed-roof tank

vertical cylindrical storage vessel with either a cone- or domed-shaped roof of either the non-pressurized (freely vented) type or the low-pressure type

[SOURCE:ISO 1998]

3.11

floating blanket

cover

screen

light-weight cover of either metal or plastic material designed to float on the surface of the liquid in a fixed-roof tank

Note 1 to entry: The blanket is used to retard the evaporation of volatile products in a tank.

[SOURCE:adapted from ISO 7507-1]

3.12

floating-roof mass

value of the floating-roof mass, inclusive of any mass load on the roof, manually entered in the data processor

3.13

floating-roof tank

tank in which the roof floats freely on the surface of the liquid contents except at low levels when the weight of the roof is taken, through its supports, by the tank bottom

[SOURCE:ISO 7507-1]

3.14

free-water level

level of any water and sediment that exist as a separate layer underneath the product

3.15

gross standard volume

volume of oil, including dissolved water, suspended water and suspended sediment, but excluding free water and bottom sediment, calculated at standard conditions

3.16

head mass

total measured mass between the HTG bottom sensor and the top of the tank

3.17

heel space

space inside the tank, below the bottom HTG sensor

3.18

HTG reference point

stable reference point from which the HTG sensor positions are measured

3.19

hydrostatic tank gauging

HTG

method of direct measurement of liquid mass in a storage tank based on measuring static pressures caused by the liquid head above the pressure sensor

3.20

in-tank vapour density

density of the gas or vapour (mixture) in the ullage space at the observed conditions of product temperature and pressure

3.21

observed density

value obtained at a test temperature which differs from the calibration temperature of the apparatus

[SOURCE:adapted from ISO 3838]

3.22

pin height

lower limit of the critical zone, i.e. the level at which the floating roof or floating blanket rests fully on its legs

3.23

product heel mass

mass of product below the bottom HTG sensor

3.24

product heel volume

observed volume of product below the bottom HTG sensor, calculated by subtracting the water volume from the total heel volume

3.25

product mass

sum of the head mass and the product heel mass, reduced by the floating-roof mass (if applicable) and the vapour mass

3.26

product temperature

temperature of the tank liquid in the region where the HTG measurements are performed

3.27

reference density

density at the reference temperature

3.28

reference temperature

temperature to which reference density and standard volumes are referred

3.29

tank average cross-sectional area

average cross-sectional area between the level of the bottom HTG sensor and the dip level, over which the hydrostatic pressures are integrated in order to obtain the head mass

3.30

tank lip

tank bottom plate on the outside of the tank shell

3.31

tank shell

outer casing of a storage tank that on land is secured to the ground and includes the roof, if it is a fixed-roof tank (3.10)

3.32

total heel volume

observed volume below the bottom HTG sensor, calculated from the level of the bottom sensor and the tank capacity table, corrected for observed temperature

3.33

total volume

indicated volume, including all water and sediment without correction for temperature and pressure.

[SOURCE:adapted from ISO 4267-2]

3.34

ullage pressure

absolute pressure of the atmosphere (air or vapour) inside the tank, above the product

3.35

vapour relative density

ratio of molecular mass of vapour (mixture) to that of air (mixture)

3.36

water volume

observed volume of free sediment and water, calculated from the free water level and the tank capacity tables

3.37

ullage

outage

capacity of the tank not occupied by the liquid

[SOURCE:ISO 7507-1]

3.38

uncertainties

unless stated otherwise, all uncertainties, including maximum permissible errors, are assumed to be extended uncertainties with coverage factor k = 2