Photodissociation of HCHO in air - CO and H2 quantum yields at 220 and 300 K

New data are presented for the quantum yields of CO and H2 produced in the photodecomposition of formaldehyde. The data were obtained at the two temperatures 220 and 300 K, as a function of wavelength in the spectral range 253-353 nm, and as a function of pressure at the wavelengths 339.3 and 353.1 nm. The influence of temperature occurs mainly on the quenching constants describing the pressure dependence. The results are compared with previous data and improved quantum yield curves are presented for applications in atmospheric chemistry. (IFU)