TotalFlow XRC6490, Руководство пользователя

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B-36
TERM DEFINITION
Polarity In electricity, the quality of having two oppositely charged poles, one positive
one negative.
Polling A snapshot view of the readings taken by the Totalflow equipment.
Port A communications connection on a computer or a remote controller. A place of
access to a device or network, used for input/output of digital and analog
signals.
Positive Temperature Co-
efficient
An increase in resistance due to an increase in temperature.
Positive Temperature Co-
efficient Fuse Opens circuit when high current condition occurs. Closes when condition no
longer exists. Replaces typical fuses, which require replacement when blown.
POU Program Organization Unit. This is Softing’s term for an ‘independent
programming unit’. Programs, functions, etc.
Power Supply A separate unit or part of a circuit that supplies power to the rest of the circuit or
to a system.
PPM Acronym for parts per million.
Pressure Base The contractual, regulatory or standard ambient pressure at which natural gas
is measured or sampled expressed in psia (pounds per square inch absolute).
Pressure Differential Difference in pressure between any two points in a continuous system.
Pressure Markers Pressure testing at different levels of pressure. Used for comparison purposes.
Pressure, Absolute See PSIA.
Pressure, Atmospheric See Atmospheric Pressure.
Pressure, Gas In the natural gas industry pressure is measured by the force applied to a
designated area. PSI and OSI refer to how much pressure (pound or ounce) is
applied to one square inch. Inches Water Column (In.W.C.) is also used to
express gas pressure and is measured using a manometer for lower pressure
readings. 1 PSIG=27.21 Inches Water Column.
Pressure, Gauge See PSIG.
Primary Cell (or Battery) A cell or battery which is not intended to be recharged and is discarded when
the cell or battery has delivered all its electrical energy.
PRM Acronym for Pressure Regulator Module.
Probe A generic term that is used to describe many types of temperature sensors.
Process Gas Gas use for which alternate fuels are not technically feasible, such as in
applications requiring precise temperature controls and precise flame
characteristics.
Program A list of instructions that a computer follows to perform a task.
Programmable Logic
Controller A highly reliable special-purpose computer used in industrial monitoring and
control applications. PLCs typically have proprietary programming and
networking protocols, and special-purpose digital and analog I/O ports.
Programmable Read Only
Memory Computer memory in which data can be written to. ROM is used for storing
programs (e.g. operating systems) and characteristic files on a permanent
basis. (non-volatile)
Programmed I/O The standard method a CPU uses to access an I/O device-- each byte of data
is read or written by the CPU.
PROM See Programmable Read Only Memory
Propane (C3H8) A saturated hydrocarbon (Alkane) gas, the molecule of which is composed of
three carbon and eight hydrogen atoms. Propane is present in most natural gas
and is the first product refined from crude petroleum. It has many industrial
uses and may be used for heating and lighting. Contains approximately 2,500
Btu per cubic foot.