A laboratory evaluation of a nitrogen dioxide personal sampling device

The Use of Passive Diffusion Tubes for Measuring Concentrations of Nitrogen Dioxide in Air

“…The effects of variations in absolute humidity on a short path sampler have also been reported, with significant reductions in uptake at low RH at low temperatures (40,42). More generally, a dependence on RH is an important factor in some passive sampler designs (36).…”

“…However, the role of the melting point of TEA was challenged by a later study (39), which showed that TEA solutions did not freeze, but formed a gel even at temperatures as low as −10 • C. The role of triethanolamine (TEA) as an absorbent is discussed below (Section 4.1). The effectiveness of TEA as an absorbent appears to be dependent on humidity, and some of the reported effects of temperature on sampling rate may be confounded by simultaneous changes in absolute humidity (40) leading to low effective sampling rates at low temperatures that are caused by a lack of water vapor rather than low temperatures per se (29,41,42). One laboratory study (designed to evaluate Palmes tubes for use in Greenland) showed almost constant sampling rates from 20 • C down to −8 • C, then a linear decrease to around 30% of the constant rate, at −28 • C (43).…”

Spatial variations in nitrogen dioxide concentrations in urban Ljubljana, Slovenia

“…In a study in Edinburgh Heal and Cape (1997) found that in urban areas this excess reached 28% in summer, while in rural areas and in winter in urban areas it was 8-14%. On the other hand, Moschandreas et al (1990) note that low temperatures (251-283 K) lead to an underestimation of NO 2 concentrations due to anomalies in the behaviour of triethanolamine below the freezing point for this substance, which is at 294 K.…”

Statistical approach for the characterization of NO2 concentrations in Beirut

“…Temperature and RH induce weak deviations on the sampling rate in comparison with the one generated by wind velocity. However, Moschandreas et al (1990) reported that low temperatures in the range of −22°C to 10°C resulted in the underestimation of nitrogen dioxide concentration because of possible anomalous behavior of the TEA below its freezing point of 21°C. In addition, correction functions should be applied under particular conditions (T>30°C and RH>80%) ).…”