Sub-Slab Soil Gas Sampling Adaptor with Segmented Interface
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Solution Overview
Problem
Current sub-slab soil gas sampling methods are cumbersome, prone to leaks, and invasive, requiring multiple installations and causing damage to slabs, with limitations in collecting samples at varying depths and risking contamination or clogging.
Innovation Solution
A device and system featuring a machined adaptor body with a single-piece construction from materials like brass or stainless steel, allowing for air-tight installation in a one-inch diameter hole, using flexible silicone tubing and barbed fittings for secure sealing, and extendable components for variable depth sampling without introducing particulates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional mini-wells with threaded fittings are used for sub-slab sampling, then sampling capability is achieved, but leaks occur at fittings and along the vapor point edge allowing indoor air to dilute the sample
Solution Approach 1:
The device divides the sampling system into separable components: a reusable adaptor body that remains installed in the slab, and removable sampling components (summa canister, tubing) that can be attached and detached. This segmentation eliminates the need for repeated disassembly/reassembly of the entire vapor point, reducing leak opportunities while maintaining sampling capability.
Solution Approach 2:
The adaptor body is pre-installed in the slab with a sealed interface before sampling occurs. The sampling components are then connected to this pre-prepared interface, eliminating the need to create seals and connections during the sampling act itself. This preliminary sealing action prevents leaks and indoor air dilution during sampling operations.
2Productivity
If vapor points are disconnected and reconnected multiple times for repeated sampling, then multiple samples can be collected, but fittings progressively loosen and leak more readily
Solution Approach 1:
The system separates the permanently installed adaptor body from the temporarily connected sampling components. Only the sampling components need to be disconnected and reconnected for repeated sampling, while the adaptor body remains fixed and sealed in the slab. This reduces the cumulative wear and loosening of fittings over multiple sampling events.
Solution Approach 2:
The adaptor body is pre-installed with a durable, reusable interface designed for multiple connections. This preliminary installation creates a stable mounting point that can withstand repeated sampling operations without degrading, allowing productivity to increase while maintaining reliability of the primary sealing interface.
3Measurement precision
If elaborate leak detection methods are implemented, then sampling accuracy is improved, but time and complexity of the sampling process increase
Solution Approach 1:
The adaptor body is pre-installed with a sealed interface that prevents leaks before sampling begins. This preliminary sealing action eliminates the need for complex leak detection methods during sampling, as the design inherently prevents the leaks that would require detection. Sample accuracy is maintained through the sealed design rather than through complex detection procedures.
4Ease of operation
If floor coverings are removed and slabs are cored or drilled for sample collection, then sub-slab access is achieved, but damage to the slab and inconvenience to occupants occur
Solution Approach 1:
The adaptor body serves multiple functions: it provides structural support for the sampling operation, creates a sealed interface with the slab, and remains in place for future sampling events. This multi-functionality reduces the need for repeated invasive installation procedures, minimizing slab damage and occupant inconvenience while maintaining ease of operation for sampling.
Solution Approach 2:
The adaptor body is installed once with a sealed interface, creating permanent access to the sub-slab space. This preliminary access creation eliminates the need for repeated coring or drilling operations for subsequent sampling events, reducing slab damage and inconvenience to occupants while maintaining easy sampling capability.
5Adaptability or versatility
If sampling is performed at multiple depths beneath the slab, then comprehensive vapor analysis is achieved, but the risk of introducing particulates and causing clogging increases
Solution Approach 1:
The adaptor body serves as an intermediary component between the slab and the sampling components. It provides a sealed interface and a controlled pathway for vapor extraction, filtering out particulates before they can enter the sampling system. This intermediary function enables variable depth sampling while preventing particulate contamination and clogging of the sampling equipment.
Data Source
AI summary
Provided are installation devices and uses thereof for receiving and installing an adaptor body for sampling soil gas under a slab. The installation device includes a cylindrical body and an internal cavity. The cylindrical body has a length greater than a thickness of the slab, a first end configured to be placed adjacent a top of the slab, and a second end configured to be placed below a bottom of the slab. The internal cavity extends longitudinally through the cylindrical body from the first end to the second end, where the internal cavity has a first portion and a second portion. The first portion has a first diameter located at the first end of the cylindrical body and the second portion has a second diameter that is less than the first diameter. The internal cavity of the cylindrical body is configured to receive the adaptor body.