The FP analysis is based on a catalytic oxidation. The analyser is first calibrated by means of a sample with known FP. The sample is mixed with preheated combustion air, both having constant flow rates, and continuously fed to the measurement cell. It is then heated up until the sample temperature in the cell reaches the known FP. At this time, the detector signal level is registered, as it corresponds to the FP of the known sample.
In the routine operatin, the sample is heated up until the detector signal level reaches the value registered during the calibration procedure. Then the sample temperature is measured in the cell, as it represents the FP of the sample under investigation. Excess sample passes to drain (overflow). The sample vapor is vented to atmosphere. The detector signal controls the incoming sample temperature.
The complete analysis procedure is controlled, monitored and visualised by the Process Analyser Control System (PACS) software. It offers a user interface for local analyser operation and for the regeneration function of the detector.
The FP value is transferred via the standard analog 4-20 mA output. A digital output signal can be generated (programmable). During the analysis, an optional, galvanically separated 4 - 20 mA signal can also be used. As an alternative, a MODBUS interface is available as an option, which also allows a direct control of the analyser from the DCS,
In case remote access to the FA is demanded, it can be equipped with a remote access interface (e.g. Modem, ISDN) for service and maintenance purposes.