CoreandServices.book - Ocean - Schlumberger

Units
Units are represented by a symbol. The symbol is a string such as “m” for meters. Often
there are multiple symbols that represent the same unit due to cultural or other reasons. A
different symbol representing the same unit is called an alias (Fig. 4-9 on page 4-199).
Aliases allow us the freedom to interchange unit representations without impact to our
application. Aliases can be used safely in unit conversion because they have unit
measurements in the catalog. However, there can be problems in other contexts due to
duplicate aliases. For example, “f” can be an alias for “farad” as well as for “ft”. When “f” is
used, the first match encountered will be returned, and this may not be the one you need.
“METER”
“METERS”
“m”
symbol
“G_LN”
“M”
“MT”
“S_LN”
aliases
Fig. 4-9 Unit Symbols and Aliases
Unit Conversion
Data that have the same base measurement can be linearly converted to use other units
associated with the base measurement. For example, the diameter of a pipe with units of
meters can be converted to other “Length” base measurement units such as feet. Data
cannot be converted between units with different base measurements. “Length” data
cannot be converted to a “Volume” data. Likewise, data that are dimensionless, such as a
phone number, cannot be converted.
Schlumberger Private
Ocean Services 4-199