# Carbon emission calculator

This online calculator allows you to calculate carbon emissions from measurements obtained by the static chamber (closed-chamber) method.

#### Chamber

Carbon emission, mg/(m²•hr)

Digits after the decimal point: 3
Chamber volume, m³

Change in CO₂ volume, m³

Molar volume, litres

Number of mol CO₂

Carbon mass, mg

Surface area, m²

Typically, a dark chamber is used that is placed on a surface, the base is sealed, and the carbon dioxide concentration in the chamber is measured over a period of time.
These measurements are used when it is necessary to determine carbon emissions in ecosystems, fields or grasslands, forest ecosystems, soils, landfills, etc. A translucent chamber can be used, in which case the carbon flux can be negative and reflect not only the emission of soil or ground, but also the contribution of photosynthetic organisms.

The calculation is performed for a single measurement session using static chamber, and we assume that the temperature and pressure in the chamber are not changed during the measurement session, as the measurements are made for a limited period of time. If the temperature and pressure change, it is recommended to calculate for the time interval when these parameters were constant. The calculation is performed using the Mendeleev-Claiperon equation.

$pV=\frac{m}{M} R T$
where
p - pressure,
V is the volume of the gas,
m is mass,
M is the molar mass,
R is the universal gas constant,
T - thermodynamic temperature.

When applying the formula, all parameters must be entered in SI units, but in this calculator you can use any units that may be at the measuring instruments, the calculator itself performs all necessary conversions. Below is a description of how to convert measurements to the SI units, which may be necessary if you perform calculations on your own.

CO₂ concentration in a static chamber is measured for a certain time, the difference between the CO₂ concentration at the end of the measurement and the concentration at the beginning of the measurement is determined. The concentration should be converted into ppm for calculation, i.e. divide the value by 1000000.

For the calculation, the temperature and pressure in the chamber during the measurement must be determined. If the temperature is measured in degrees Celsius, it must be converted to Kelvins. For this purpose, 273 is added to the temperature value in degrees Celsius to obtain the value in Kelvin.

If the measurement was made in millimetres Hg, it must be converted to Pascals. To do this, the mmHg value is divided by 760 and multiplied by 101325.

It is necessary to calculate the volume of the chamber in which the measurement was carried out (this calculation is performed for chambers in the form of a parallelepiped, cylinder, sphere segment or hemisphere), the volume should be converted into litres.

After converting all data into the required units, the Mendeleev-Claiperon equation can be applied and the volume of gas in the chamber can be calculated. The calculator then calculates the number of moles of carbon dioxide released during the measurement time by multiplying the ppm CO₂ during the measurement time by the volume of gas in the chamber.

To calculate the mass of carbon in the chamber during the measurement time, multiply the number of moles of carbon dioxide by the molar mass of carbon 12.

Now you can calculate the carbon flux per unit time per unit area, i.e. divide the obtained value by the area of the chamber base and by the measurement time, this calculator calculates the flux in units of C/m²•sec.

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PLANETCALC, Carbon emission calculator