DL-300 Data Logger User Manual Version 1.1.0 Aug. 2015
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8. FAQ
Q1: What is ABC (Automatic Baseline Correction)?
A: ABC stands for the Automatic Baseline Correction which is used to adjust a shifted
baseline to the carbon dioxide level in fresh air. In case of normal indoor application,
the carbon dioxide level drops to nearly outside air where there are no human, green
plants or anything to elevate the carbon dioxide levels on weekday evenings or
weekends, the ABC algorithm constantly keeps track of the lowest reading and slowly
corrects it as the expected value in fresh air typically around 400 ppm.
Q2: Why I need to enable the ABC?
A: When the CO
2
concentration detected in a period time of unoccupied space is
greater than the base value of 400ppm, enable the ABC function to adjust the
baseline. Be careful that the ABC will not work if a space is constantly occupied such
as a hospital, 24-hr factory, 24-hr store, green house or other applications where CO
2
levels may be elevated at all times.
Q3: Does the DL-302/DL-303 enable the ABC as the factory default setting?
A3: No, the ABC is default disabled in a DL-302/DL-303 logger to prevent the baseline
from being adjusted to an incorrect value in case of using in a constantly occupied
space.
Q4: What to do when the ABC is no work?
A4: When the ABC is no work regarding baseline correction, the DL-302/DL-303 needs
be returned to ICP DAS.