CO2 Meter - How the TWA Reading is Calculated

The CO2 Meter (Carbon Dioxide) offers a TWA (Time Weighted Average) reading in addition to the instantaneous CO2 reading. See the formula to calculate this value below.

[For the TWA formula of the CO (Carbon Monoxide) Meter, go here.]

TWA Formula

Every time the sensor takes a CO2 reading, per the measurement interval, it logs the reading and the amount of time that reading was taken to an array. The sensor also recalculates the TWA based on this array on each reading. The calculation sums each CO2 reading multiplied by the associated time in seconds till the amount of time summed exceeds 8 hours, then divides the product summation by the summed time. The smallest amount of time to be saved to the array is 1 minute, so the TWA should update every minute.

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