DL-300 Data Logger User Manual Version 1.1.0 Aug. 2015
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4.6 I/O Settings
Users can change the temperature unit to Fahrenheit or Celsius in this field.
To Enable/Disable the CO
2
Automatic Baseline Correction function. It is supported on
the DL-302 and DL-303 only.
Q & A
Q: 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.
Q: 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.