TotalFlow XRC6490, Руководство пользователя

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B-42
TERM DEFINITION
Specific Gravity The ratio of the mass of a solid or liquid to the mass of an equal volume of
distilled water at 4°C (39°F) or of a gas to an equal volume of air or hydrogen
under prescribed conditions of temperature and pressure. Also called
relative
density .
Speed of Gas Rate at which gas travels through the pipeline. Used in flow calculations in the
TotalSonic Meter. Calculations follow AGA 9 Report.
Speed of Sound Rate at which sound travels through the medium. Used in flow calculations in
the TotalSonic Meter. Calculations follow AGA 10 Report.
SPU Signal Processing Unit (measurement transducer).
SQL See Structured Query Language.
SRAM See Static Random Access Memory
SSM Acronym for Stream Selector Module.
ST Structured Text (IEC supported programming language)
Stability The quality of an instrument or sensor to maintain a consistent output when a
constant input is applied.
Stable Gas Is a vapor containing less than 0.1 PPM of liquid when vapor is cooled to
18.3
° F (10 ° C) below the coldest ambient temperature possible at any point in
the system.
Static Pressure Equals PSIA or PSIG. Referenced to atmospheric pressure versus absolute
pressure in a vacuum. It is defined as the pressure exerted by a non-moving
liquid or gas. In the case of a gas well this would be the natural PSI of the gas
inside of the well.
Static Random Access
Memory The place in your computer that programs reside when running. You can
access any part of the memory, and it can easily be overwritten with new
values. SRAM is much more expensive and physically larger than DRAM but
much faster.
Status Output Any digital output that uses “On” or “Off” conditions to determine the status of
the assigned description. Changing from one to the other represents a change
in the condition.
STP Standard Temperature and Pressure
Structured Query
Language IBM developed this language in the 60’s as a way of accessing data from a
relational database. It has a very simple syntax for simple functions but can
become complex for sophisticated applications. This language is standardized
by international standards bodies, and is almost universal in application. Almost
all databases support SQL. The iVision RTDB supports SQL and this makes it
extremely flexible within a corporate network. Authorized users throughout the
organization can write SQL statements to acquire data from this database that
they need for Marketing, Accounting, Engineering, or other functions.
Sulfur
A pale, yellow, non-metallic chemical element that may be found in a gas
stream and which needs to be removed or reduced from the gas stream for
corrosion control or health or safety reasons.
Supercompressibility
Factor A factor used to account for the following effect: Boyle's law for gases states
that the specific weight of a gas is directly proportional to the absolute pressure,
the temperature remaining constant. All gases deviate from this law by varying
amounts, and within the range of conditions ordinarily encountered in the
natural gas industry, the actual specific weight under the higher pressure is
usually greater than the theoretical. The factor used to reflect this deviation
from the ideal gas law in gas measurement with an orifice meter is called the
"Supercompressibility factor Fpv". The factor is used to calculate corrected from
volumes at standard temperatures and pressures. The factor is of increasing
importance at high pressures and low temperatures.