Teledyne API T803 CO2/O2 Analyzer Operation Manual Principles of Operation
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12.6.11. CALIBRATION - SLOPE AND OFFSET

Calibration of the analyzer is performed exclusively in software.
During instrument calibration the user enters expected values for span via the
front panel touchscreen; values are not entered during a zero operation,
commanding the instrument to make readings of calibrated sample gases for both
levels. The readings taken are adjusted, linearized, and compared to the expected
values. With this information the software computes values for instrument slope
and offset and stores these values in memory for use in calculating concentrations
of the sample gas.
The instrument slope and offset values recorded during the last calibration are
available for viewing from the from the front panel (See Section 3.5.1)

12.6.12. TEMPERATURE AND PRESSURE COMPENSATION

Changes in ambient pressure can have a noticeable effect on the CO2 and O2
concentration calculations. To account for this, the T803 software includes a
feature which allows the instrument to compensate both CO2 and O2 calculations
based on changes in ambient pressure. Both sensors are housed inside
temperature controlled manifolds. This minimizes temperature effects on the
measured concentrations.

12.6.13. INTERNAL DATA ACQUISITION SYSTEM (DAS)

The DAS is designed to implement predictive diagnostics that stores trending
data for users to anticipate when an instrument will require service. Large
amounts of data can be stored in non-volatile memory and retrieved in plain text
format for further processing with common data analysis programs. The DAS
has a consistent user interface in all Teledyne API analyzers. New data
parameters and triggering events can be added to the instrument as needed.
Depending on the sampling frequency and the number of data parameters the
DAS can store several months of data, which are retained even when the
instrument is powered off or a new firmware is installed. The DAS permits users
to access the data through the instrument’s front panel or the remote interface.
The latter can automatically download stored data for further processing. For
information on using the DAS, refer to Section 7.1
07276B DCN6418