Instruction manual

Instruction Manual
760006-A
September 2001
Rosemount Analytical Inc. A Division of Emerson Process Management Preface P-7
Model NGA 2000 Platform
Polynomial
A mathematical term meaning an expression (a function of a variable) containing several terms, each of
which contains a power of the variable. A + B X x + C X (x X x) is a second order polynomial in x. A,B and
C are its zeroth, first and second coefficients. "X" means multiply, as usual.
Power Supply Board
The Power Supply Board that plugs into the front of the Backplane capable of supplying power (+24 VDC
@ 5 Amperes) to the platform components and just one Analyzer module mounted within the platform.
Primary Variable
The measured species concentration value from an Analyzer module.
Range
The bounds of concentration over which the Analyzer's reading is accurate, or possible. Traditionally this
is set by the Analyzer circuitry or its physics: in NGA 2000, it is often merely a mathematical fiction pro-
vided for operational convenience.
Response Factor
The relative response of the Analyzer to different gases to which it is sensitive. In the case of the FID this
refers to its response to various hydrocarbons, which is roughly in proportion to the number of carbon at-
oms contained in the gas' molecule.
Safety Failure
Indicates a failure of the Analyzer safety system, with resultant shut down of the Analyzer.
Secondary Variable
The current status data placed on the network by an Analyzer module. The includes sample flow, source
voltage and other diagnostic information.
Serial Number
A number assigned to the module at time of manufacture. It is stored in the network variable AMSN, and
marked on a label on the module enclosure.
Softkeys
The five function keys located below the front panel display. The menu function for each softkey is dis-
played directly above it and is controlled by the software.
Solenoid Valves
A gas switching element controlled by electrical current. It is used to control the flow of sample or calibra-
tion gas to an Analyzer.
Span
The range over which something works, or the act of standardizing the upper end of the range.
System
A NGA 2000 System consisting of one (or more) Analyzer modules, an optional Platform, one or more op-
tional I/O Boards, an optional Expansion Board and an optional 30 A Bulk Power Supply.
System Integrator
An individual or organization who designs and builds analytical systems. Typically these are panels con-
taining one or more Analyzers together with the sample system components and any other devices re-
quired for stand-alone operation.