Emerson IM-106-5500 Manual Do Utilizador

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Instruction Manual
IM-106-5500, Original Issue
August 2005
CCO 5500
1-4
Signal Processor Unit 
The signal processor unit is housed in a fully-sealed cast-aluminum 
enclosure. It houses the microprocessor to monitor the data from the receiver 
and produces a 4-20 mA output signal for gas levels within the flue. 
A non-volatile RAM section - requiring no battery back-up - enables all of its 
operation data to be retained during a power down condition. The instrument 
can resume operation immediately when power is restored without having to 
be recalibrated. 
All operation data is entered via a surface-mounted keypad. A 32-character 
LCD provides the operator with measurement details and diagnostic 
information. 
Inputs are available to receive the 4-20 mA outputs of normalizing 
measurement transducers - O
2
, temperature and pressure, if required. This 
data can also be entered via the keypad or via the serial data port. 
A serial communication facility within the processor allows the instrument to 
communicate with other Rosemount analyzers and a central data logging unit. 
Power Supply Unit 
The power supply unit is housed in a fully-sealed cast-aluminium enclosure 
and contains the power supplies for the instrument. A switched mode power 
supply is utilized to provide an extremely stable power source, able to cope 
with large fluctuations in the supply voltage. The contact outputs are also 
taken from this unit - data valid and high gas alarm. 
Air Purge 
The air purge unit has its own integral adjustable mount and provides the 
interface between the site mounting flange and the transmitter and receiver 
units. The purge is designed to provide a steady laminar flow of air away from 
the instrument lens, preventing optical contamination. 
A supply of air to the purge is essential. 
Isolating Valves 
Isolating valves, if required, may be attached between the air purges and the 
duct. These will allow protection for personnel servicing instruments on high 
pressure ducts. 
PRINCIPLES AND 
MODES OF OPERATION 
Calculation of Gas 
Concentration 
Gas levels are determined by measuring the absorption of infrared radiation, 
transmitted through the flue gas, in a wave band sensitive to absorption by the 
measurement gas. CCO 5500 monitors have two detectors; one measures 
the radiation directly to provide a live output, sensitive to the measurement 
gas, while a second detector measures the radiation after passing through a 
gas cell filled with pure reference gas (CO), to provide a reference 
measurement, completely unaffected by the measurement gas.