9-32 Chapter 9: Inspection and Maintenance 42/24-10 EN Rev. 9Cross-Sensitivity AlignmentElectronic Cross-Sensitivity CorrectionAO2000 offers the ability to electronically correct cross sensitivity, in contrast tousing purely physical methods (for example, for infrared absorption, optical filteror flowing reference gas).Electronic cross sensitivity correction is possible with the Caldos25, Caldos27,Limas11, Magnos206 and Uras26 analyzer modules. In addition, this function mustbe factory-set per customer order. It is configured as a function block application.A detailed description of the function block Cross sensitivity correction iscontained in the Technical Bulletin “AO2000 Function Blocks – Descriptions andConfiguration” (Publication No. 30/24-200 EN).Cross sensitivity correction is an offset correction.Interference component concentration is continuously measured and corrected bymeans of the measurement value. Alternatively, the interference component con-centration can be entered directly as a correction value during the cross sensitivityalignment.Internal and ExternalCross SensitivityCorrectionInterference component concentration can be measured in two ways:• Using the analyzer module with which the sample component is measured(internal cross sensitivity correction, possible only with the Limas11 and Uras26analyzer modules) or• With another AO2000 analyzer module or another analyzer (external crosssensitivity correction) The correction signal, i.e. the measured value of theinterference component is transferred to the analyzer module with the samplecomponent to be corrected via the system bus or analog input.When should a crosssensitivity alignmentbe performed?A cross sensitivity alignment, i.e. alignment of the cross sensitivity correctionfunction, should not be performed in normal operation.We recommend checking the cross sensitivity correction once a year.Test Gas for CrossSensitivity AlignmentOne of the following test gases is needed for the cross sensitivity alignment:• Either a sample component-free test gas containing the maximumconcentration of the interference component• Or the interference component span gas.Prior to the CrossSensitivity AlignmentPrior to the cross sensitivity alignment, the zero and end points of the applicablesample and interference components must be calibrated with test gases in therespective analyzer module.Menu Path MENU → Maintenance/Test → Analyzer spec. adjustm. →Cross sensitivity adjustm.
