The partial pressure of the ozone is a measure for local ozone concentration. Sometimes ppmv values are used. Basic principles for this step of the calculations are given in the sensor manufacturer's manuals. See Related Manuals. As each molecule of ozone creates a current of two electrons, ozone concentration is:
- C
- Ozone concentration in mmol 1-1
- F
- 9.6485 × 104 C (mol)-1 (Faraday constant)
- I
- measured current in μA
- t
- pumping time for 100 ml of air (seconds)
The partial pressure of ozone (P3) is:
R = 8.31451 JK-1 mol-1 (Molar gas constant)
Finally:
- P3
- Partial pressure of ozone in mPa
- I
- Measured ozone current in μA
- IBG
- Current caused by oxidants other than ozone (mainly O2) in μA (IBG equals to IB2).
- Tp
- Measured airflow temperature in K from pump base.
- t
- Pumping time for 100 ml of air in seconds
- Cef
- Correction due to reduced ambient pressure for pump
- Cref
- Additional correction factor
| IBG used in this manual is equal to I0 used in the Vaisala scripts, and IB2 used in the GAW report 201, and the ASOPOS panel recommendations. |
|
Each ozone sensor manufacturer has their own recommendations for calculating IBG, Tp, and Cef. See Related Manuals. |