Introducing Entech’s breakthrough technology for whole air sample collection
Helium Diffusion Sampling (HDS™)
Introducing Entech’s breakthrough technology for whole air sample collection – Helium Diffusion Sampling (HDS™). We now offer HDS™ active sampling solutions for indoor air monitoring that simplify the collection of airborne chemicals for GC and GC/MS analysis. Rather than performing a traditional vacuum sampling event, MiniCans and Bottle-Vacs™ are initially filled with helium, or helium with a recovery surrogate, and active sampling occurs in response to the controlled exchange of helium with air through a diffusion region. An HDS™ diffusion zone’s internal diameter is 20–50 times larger than typical critical orifice samplers, so particulate plugging is virtually impossible. HDS™ eliminates the need for sampler calibration, as relative diffusion rates of Helium and air are virtually constant. And unlike passive sampling with tubes – where compounds lighter than Benzene are not recovered quantitatively – HDS monitoring recovers all compounds heavier than Helium. Some important carcinogenic compounds quantitatively recovered using HDS that are not recoverable using passive tube sampling devices include: Vinyl Chloride, 1,3-Butadiene, and Acrolein. HDS™ Samplers also increase their weight as more air exchanges with Helium, allowing sample collection amounts to be determined gravimetrically in the laboratory for extremely accurate and defensible measurements.