Sampling soil gas into canisters provides significant advantages over the use of passive adsorbent samplers with regard to both maintaining the integrity of the sample in the field and ensuring that the best analytical technique is used in the laboratory.

Canisters eliminate the need for pumps, batteries, and media selection, and the same sampling approach can be utilized for any gas concentration while being universal for all compounds. Furthermore, humidity and temperature concerns inherent with tube sampling do not affect canister accuracy.

Entech has a long history of engineering turn-key solutions specific to the environments being sampled. Designed with feedback from numerous sampling professionals, the Chameleon provides an all-in-one solution that is changing the way soil gas studies are conducted world-wide.

The Chameleon enhances soil gas sampling accuracy by employing fundamental gas chromatography principles. To obtain a representative vapor sample from the soil, it is crucial to modulate the sample flow rate in accordance with the soil’s diffusion rate. Failure to do so may result in soil study samples overly concentrating chemicals within the fastest diffusion pathways, leading to a potentially unrepresentative depiction of the area’s true chemical composition. This could introduce biases, skewing the results either too low or too high. The Chameleon is optionally equipped with a down-hole vacuum gauge which ensures that the flow rate is in line with a safe permeation rate for the given sampling location.

As importantly, sampling systems must be considered an extension of the laboratory. The Chameleon Soil Gas Sampler achieves this by;

• Ensuring all surfaces are inert using Entech Silonite™ coated stainless steel.
• Minimizing surface area and shortening path lengths to canister.
• Minimizing leak prone connections by providing custom engineered flow path connectivity solutions.
• Eliminating absorption (no plastic tubing where possible) .
• Proving the entire system is leak-tight before delivery to field.
• Isolating the flow path from the outside world during transportation.

• The Chameleon can be configured to minimize compression fittings based on the probe, line, or fitting to which it connects.
• The inlet and outlet can be configured separately to optimize the sample train.
• The down hole vacuum gauge monitor can be added to any configuration, and verifies that excessive vacuum is not forming in the soil (<7.3” Hg vacuum).
• All configurations can be maintained under positive gas (N2) pressure during shipment to the field to perform the shut-in test (leak test) automatically.
• Chameleons may be equipped with the popular Micro-QT fittings for quick-connections from the soil or slab interface to the canister.