VSA Vapor Sorption Analyzer

Simple instrument—advanced scientific breakthroughs

If you want to understand complex soil issues like clay behavior, specific surface area, shrink-swell capacity, or cation exchange capacity, the VAPOR SORPTION ANALYZER (VSA) is your simplest, most accurate option. It automates the entire process of soil water characteristic curve construction in the dry region (-10 to -475 MPa) by accurately measuring simultaneously, at regular intervals, the water potential and the moisture content of a sample. No other instrument gives this much detail about soil in the dry range.

Delve deeper into your dry soil analysis

The VSA enables you to make detailed measurements no other instrument can. This means you can study the soil at a particle level, examining its chemical makeup and how the layers of soil imbibe water as it gets wetter or lose water as it gets drier. For the first time ever, it’s possible to see hysteresis in dry soils because the VSA analyzes both wetting and drying curves. This is critical information because the area between those curves is indicative of water intrusion into clay layers at the molecular level.

The VSA generates both Dynamic Dew Point Isotherm (DDI) and Dynamic Vapor Sorption (DVS) soil water characteristic curves. How? It continuously wets the sample and stops periodically to measure how heavy it is (DDI), or it keeps the sample at a constant humidity, recording how long it takes the sample to come to equilibrium (DVS). In just 24 to 48 hours, the VSA generates curves with up to 200 data points (water potential vs. water content) for both adsorption and desorption.

Set up a test, and walk away

With the VSA, it takes about five minutes to set up a test. Simply tell the instrument the water potential range and times you’d like to use, put the sample into the instrument, and move on to other tasks. The data from your test are automatically recorded and sent to your computer. Powerful automation adds up to powerful time savings.

Explore new frontiers in science

What’s the next great scientific advancement that’s going to be made with this instrument? Only you can say. The VSA’s incredibly detailed soil water characteristic curves let you research complex soil behaviors no one’s yet explored. Sophisticated information and powerful efficiency make it easier than ever to draw accurate conclusions about your soil’s behavior, its expansibility, its makeup, and its performance as an engineering material.