TotalFlow XRC6490, User Manual

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B-5
TERM DEFINITION
Atmosphere (one) A unit of pressure; the pressure that will support a column of mercury 760 mm
high at 0 °C.
Atmospheric Pressure The pressure exerted on the earth by the earth’s atmosphere (air and water
vapor). A pressure of 760 mm of mercury, 29.92 inches of mercury, or 14.696
pounds per square inch absolute is used as a (scientific) standard for some
measurements. Atmospheric pressure may also refer to the absolute ambient
pressure at any given location.
Audio Frequency Generally in the range 20 Hz to 20 KHz.
Audit To examine or verify data for accuracy. Totalflow’s DB1 and DB2 records may
be edited to generate a more accurate representation of data information.
Audit Trail Using the Long Term Archive files to justify changes made to records that more
accurately reflects the correct data. Peripheral information used to edit data is
recorded without exception, to justify the accuracy of the edited data records.
Automatic Frequency
Control Similar to Automatic Fine Tune (AFT). A circuit that keeps a receiver in tune
with the wanted transmission.
AWG American Wire Gage.
AWG Acronym for American Wire Gauge.
Back Pressure Pressure against which a fluid is flowing. May be composed of friction in pipes,
restrictions in pipes, valves, pressure in vessels to which fluid is flowing,
hydrostatic head, or other resistance to fluid flow.
Backflush Technique used in chromatography to reverse direction of the flow after the
lighter components have been measured, allowing the heavier components to
remain in the column until measured, shortening the length of the column.
Background Acquisition Data is acquired by a DAQ system while another program or processing routine
is running without apparent interruption.
Background Noise The total noise floor from all sources of interference in a measurement system,
independent of the presence of a data signal.
Backup A system, device, file or facility that can be used as an alternative in case of a
malfunction or loss of data.
Bandwidth The range of frequencies available for signaling; the difference between the
highest and lowest frequencies of a band expressed in Hertz.
Bar Bar is equal to 1 atmosphere of pressure. I.e. .987 Standard atmospheric
pressure or 14.5 lbs./psia.
Barometer An instrument which measures atmospheric pressure.
Barrel A unit of liquid volume measurement in the petroleum industry that equals 42
U.S. gallons (.159 cubic meters) for petroleum or natural gas liquid products,
measured at 60 degrees Fahrenheit and at an equilibrium vapor pressure.
Base Pressure The pressure used as a standard in determining gas volume. Volumes are
measured at operating pressures and then corrected to base pressure volume.
Base pressure is normally defined in any gas measurement contract. The
standard value for natural gas in the United States is 14.73 psia, established by
the American National Standards Institute as standard Z-132.1 in 1969.
Basic Sediment and Water Waste that collects in the bottom of vessels and tanks containing petroleum or
petroleum products.
Battery Two or more electrochemical cells electrically interconnected in an appropriate
series/parallel arrangement to provide the required operating voltage and
current levels.
Baud Unit of signaling speed. The speed in baud is the number of discrete conditions
or events per second. If each event represents only one bit condition, baud rate
equals bits per second (bps).