Emerson Rosemount CCO 5500, Reference Manual

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E1 and E2 are the detector levels with the gas cell within the source unit in the sight path
and will be roughly
½ of the D2 and D1 levels. The analyzer may also display smoothed
detector values; these are noted as d1, d2, e1, and e2.
Sat. # indicates whether the detector signals are saturating within the micro-processor
(this value should always be zero). If it displays a number other than zero, it indicates
saturation, and you should adjust the detector gain. Refer to
Section 3.5 .
Phase is the time correction applied for the calculation of the detector levels. This will be
between 0.1 and 5.9 milliseconds. The instrument calculates this value, and you may not
adjust it.
4.9.2 Modulation (chopper motor) frequency
The chopper blade should chop the IR radiation at a frequency of about 37 Hz. The
processor measures this frequency and displays it from this option.
As the chopper blades interrupt the IR beam, they split the radiation into two. Half the
time the blade obscures the beam, and half the time the beam radiates across the duct.
The value of Mark/space should be between 0.9 and 1.1 where:
Mark/space = Time IR beam obscured/Time IR beam clear.
4.9.3 YVals and CO ppm
A parameter Y determines the calculation of the gas concentration; refer to Section A.7.5 .
As a check on the program operation, you may view this parameter and the resulting raw
gas calculation here.
The term Yx is the second averaging stack's held value, and the term Y(60) is the 60-
second raw value from which all of the other averaging stacks are calculated. These gas
values represent the raw data before averaging for the corresponding Y values. You can
also display the Z values by pressing the arrow keys. The Z values are the adjusted Y values
used to compensate for cross sensitivities in the measurement range.
Operation
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