2.2.5. EC Laboratory Calibration Protocol

The EC cells (NO₂-B43F [49] and OX-B431 [50]) are produced by Alphasense and each cell is tested in a single pass setup, yielding zero current (nA) and sensitivity (nA ppm⁻¹) values, prior to dispatch [53]. Tests are conducted with a flow of 5 L min⁻¹, T of 22±2 °C and RH of 45±15%. Alphasense is confident in the linearity of cell response within the specified measurement range (0–20 ppm) and therefore only test at pollutant concentrations of zero ppb, and one known concentration (not disclosed). Tables of sensitivities and zero values for the cells are included in the Appendix A (Table A1 and Table A2).