Tech Focus: FROG Meter
When evaluating the potential for vapor intrusion (VI) in a building, it is both important to understand does VI exist and if so, the associated source and pathway. The pathway of VI is often through an imperfect building slab. However, VI can also be the result of preferential pathways into the building (e.g. drain) that are not mitigated by these conventional measures. But then how do you effectively and efficiently identify the source of VI?
Most commonly, screening of building interiors is conducted with a handheld photoionization detector that measures total volatile organic compounds by collecting 8-hour or 24-hour indoor air samples for laboratory analysis. While indoor air screening is an efficient methodology that provides real-time information, the results lack specificity regarding the exact volatile compound present and thus often overlook potential pathways. Indoor air sampling, which is specific and accurate, generalizes results over the sampling window and does not provide real-time feedback used to tailor a sampling strategy in the field. Thankfully, there is a third option that can provide specific, accurate, and real-time information while efficiently screening the indoor of a building: the FROG-5000TM meter developed by Defiant Technologies.
The FROG meter is a handheld device that collects discrete air samples and, through portable gas chromatography, provides real-time analytical results to evaluate the presence of a particular compound in indoor air at trace levels. Since the results are received in real-time, the overall field screening effort can be tailored based on the observations of the FROG meter, with select confirmatory samples collected for laboratory analysis. By tailoring the screening, the likely pathway and source of VI can often be identified more quickly and accurately. The FROG meter adds another tool to an environmental engineer’s toolkit, allowing them to perform field screening for VI in an even more effective, timely, and cost efficient manner.