A survey of nitrogen dioxide concentrations in the United Kingdom using diffusion tubes, July–December 1991

Statistical approach for the characterization of NO2 concentrations in Beirut

“…The greatest effect is observed for the wind velocity with a significant increase of sampling rate (Bush et al 2001;Campbell et al 1994;Plaisance et al 2004). This effect, expressed in terms of reduction in diffusion length, is 47% for air velocities close to 2 m s −1 ) and can be limited by a physical protection of the tube.…”

“…Being a low-cost, convenient way of mapping spatial distributions and investigating long-term trends of NO 2 , these passive diffusion tubes (PDT) are widely used for ambient air monitoring as well (Campbell et al 1994;Ferm and Svanberg 1998;Gair and Penkett 1995). Since the uptake rate is quite low, this method requires long exposure periods (1 to 4 weeks).…”

Spatial variations in nitrogen dioxide concentrations in urban Ljubljana, Slovenia

“…First of all we are interested in the comparability of this method with the reference method. The use of diffusive samplers compared with the reference method approved by the European Commission was performed by Warren Spring Laboratory (Campbell et al, 1994) and researchers found that the use of diffusive samplers gave about 30% higher values, with the differences being higher in more heavily polluted environments. A possible source of the elevated concentrations could be wind effects, shortening the diffusion path in the diffusion tube (Campbell et al, 1994).…”

“…The use of diffusive samplers compared with the reference method approved by the European Commission was performed by Warren Spring Laboratory (Campbell et al, 1994) and researchers found that the use of diffusive samplers gave about 30% higher values, with the differences being higher in more heavily polluted environments. A possible source of the elevated concentrations could be wind effects, shortening the diffusion path in the diffusion tube (Campbell et al, 1994). Several studies (Heal et al, 1999;Heal and Cape, 1997) show the higher concentrations of nitrogen dioxide to be the result of change in the atmospheric photostationary state within the tube, where there is a reaction between nitrogen monoxide and ozone that is no longer balanced by the dissociation of nitrogen dioxide.…”

The Use of a New Passive Sampler for Ozone and Nitrogen Oxides Monitoring in Ecological Effects Research

“…Originally developed in the field of occupational hygiene, the Palmes sampler was first introduced for monitoring ambient NO 2 by Atkins [8] and since then it has been widely used for studies in urban and rural areas and for deployment in UK national surveys [9,10,11]. As far as the determination of NO is concerned, the idea at the basis of the few applications presented in the literature is to oxidise NO to NO 2 followed by collection on TEA.…”