Combined NO2/SO2 Technical Data Sheet

Technical Data Sheet: TDS 3 DIF 500 RTU-RA - COMBINED NITROGEN DIOXIDE (NO2) AND SULFUR DIOXIDE (SO2) DIFFUSION TUBE Description: Acrylic tube fitted with a green and white thermoplastic rubber caps. The green cap contains the absorbent and the white cap is fitted with a filter to prevent the ingress of particulates. This tube is designed to simultaneously passively monitor gaseous NO2 and SO2. Analysis of exposed tubes is carried out by Ion Chromatography (ISO Accredited Methods). This tube is suitable for carrying out spatial or localized assessments for NO2 / SO2 in ambient air. It can be used for co-location projects alongside an automatic analyzer but it is not recommended for bias comparison measurements. For this application separate NO2 and SO2 diffusion should be employed. Tube Dimensions: 71.0mm length x 11.0mm internal diameter. Recommended Exposure Periods: 2 – 4 weeks. Air Velocity: Influence of wind speed: Sampling rate does not vary between 1.0 and 4.5 msec-1 (*based on original data). Storage: Store in a dark, cool environment preferably between 5-10°C. Shelf Life: 12 weeks from preparation date. Desorption Efficiency: d = 0.98 (determined using N.I.S.T. Standard Analytes). Limit of detection: NO2: Less than 0.5 ugm-3 over a 4-week exposure period. SO2: Less than 1.5 ugm-3 over a 4-week exposure period. Specific values available upon request. Analytical Expanded Measurement Uncertainty: available upon request. Relevant Standards: BS EN 13528 Parts 1-3: 2002/3. Special Factors: Potential interference from nitrous acid, peroxy acetyl nitrate, and sub- micron sulfur loaded particulates, which could increase levels of nitrate and sulfate. TDS 3:V1 March 2012