Teledyne gfc 7000ta operation manual Default DAS Channels

Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer

6.7.1.3. DAS Triggering Events

Triggering events define when and how the DAS records a measurement of any given data channel. Triggering events are firmware-specific and a complete list of Triggers for this model analyzer can be found in Appendix A-5. The most commonly used triggering events are:

∙ATIMER: Sampling at regular intervals specified by an automatic timer. Most trending information is usually stored at such regular intervals, which can be instantaneous or averaged.

∙EXITZR, EXITSP, SLPCHG (exit zero, exit span, slope change): Sampling at the end of (irregularly occurring) calibrations or when the response slope changes. These triggering events create instantaneous data points, e.g., for the new slope and offset (concentration response) values at the end of a calibration. Zero and slope values are valuable to monitor response drift and to document when the instrument was calibrated.

∙WARNINGS: Some data may be useful when stored if one of several warning messages appears such as WTEMPW (GFC wheel temperature warning) or PPRESW (purge pressure warning). This is helpful for trouble-shooting by monitoring when a particular warning occurred.

6.7.2.Default DAS Channels

A set of default Data Channels has been included in the analyzer’s software for logging CO2 concentration and certain predictive diagnostic data. These default channels include but are not limited to:

CONC: Samples CO2 concentration at one minute intervals and stores an average every hour with a time and date stamp. Readings during calibration and calibration hold off are not included in the data. By default, the last 800 hourly averages are stored.

PNUMTC: Collects sample flow and sample pressure data at five minute intervals and stores an average once a day with a time and date stamp. This data is useful for monitoring the condition of the pump and critical flow orifice (sample flow) and the sample filter (clogging indicated by a drop in sample pressure) over time to predict when maintenance will be required. The last 360 daily averages (about 1 year) are stored.

CALDAT: Logs new slope and offset every time a zero or span calibration is performed. This Data Channel also records the instrument readings just prior to performing a calibration. This information is useful for performing predictive diagnostics as part of a regular maintenance schedule (See Section 9.1).

STBZRO: Logs the concentration stability, the electronic output of the IR detector of the most recent measure phase and the measure/reference ratio every time the instrument exits the zero calibration mode. Data from the last 200 zero calibrations is stored. A time and date stamp is recorded for every data point logged. This information is useful for performing predictive diagnostics as part of a regular maintenance schedule (See Section 9.1).

STBSPN: Logs the electronic output of the IR detector of the most recent measure phase and the measure/reference ratio every time the instrument exits span calibration mode. Data from the last 200 zero calibrations is stored. A time and date stamp is recorded for every data point logged. This information is useful for performing predictive diagnostics as part of a regular maintenance schedule (See Section 9.1).

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