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The gas analyzers have extensive functions for device diag- nostics and thus for corrective maintenance. In addition, they are capable of detecting functional irregularities. These ap- pear as a maintenance requirement or as a failure alarm in the display of the Maintenance Station, at the signal output, or they are signaled via PROFIBUS PA/DP to higher-level systems. The messages are recorded in a logbook.

Possible causes for maintenance requests include:

Calibration tolerance exceeded due to pollution of measu- rement chamber, drift or change of the calibration gas

Use of incorrect test or comparison gas

Detector defective or comparison gas failed

Monitoring of external interfering signals, e.g. for sample preparation for the OXYMAT 6:

-Maximum sample chamber or measuring head tempera- ture exceeded

-Heating is defective

-Zero or comparison gas contains too much oxygen

-Monitoring of the magnetic field

For FiIDAMAT 6:

-Combustion gas failure or flame extinguished

For ULTRAMAT 6 and ULTRAMAT 23:

-Flow monitoring

-Monitoring of the chopper motor

For LDS6:

-Monitoring of the transmission of the transceiver unit

Process gas chromatography

MAXUM edition II

A universal usable gas chromatograph, which provides nu- merous analytical options thanks to its modular structure. This means that widely varying measuring tasks can be implemen- ted using only one device platform. "Parallel chromatogra- phy", in which a complex analytical task is divided into several simple simultaneous measurements, is possible.

MicroSAM

A compact, space-saving gas chromatograph to the fast, dis- continuous analysis of gaseous samples. The use of standar- dized application modules permits the easy replacement of modules, instead of repair on site.

SITRANS CV

A gas chromatograph specially developed for precisely deter- mining calorific values. Based on the proven microsystem technology of the MicroSAM and suited for custody transfer.

Comprehensive maintenance and diagnostics information is made available to the Maintenance Station via an OPC server or via Modbus.

Process gas chromatography

Analyzer System Management

ASM is a SIMATIC WinCC-based software system that was de- veloped to monitor, validate and conduct performance checks on various types of analyzers, facilitate maintenance work, and to record trends.

The complete range of functions of an ASM system encompas- ses an independent analyzer network and programmable con- trollers to integrate third-party devices as well as engineering that allows the customer-specific plant requirements to be dis- played in the ASM system. ASM can be integrated on a SIMA- TIC PCS 7 platform or it can be implemented on its own work- station as an independent solution.

Remote service

The remote service combines process analytics with state-of- the-art information technology. Thus, various services which previously required on-site intervention can now be offered via a data line.

Siemens provides a remote service center, from which the analyzers can be directly accessed for preventive and correcti- ve measures.

Currently, this service is offered for the MAXUM, MicroSAM and SITRANS CV gas chromatographs and for the LDS6 diode laser gas analyzer. For optimal data security, proven mecha- nisms such as encryption, VPN, or call-back functions are used.

Advantages: Significantly improved system availability and ef- ficiency of the analytics with reduced downtimes.

20Monitoring and diagnostics

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Siemens SIMATIC PCS 7 Process gas chromatography, Maxum edition, MicroSAM, Analyzer System Management, Remote service