Isotherms made easier.

Create dynamic, high resolution moisture sorption curves in days, not months.


Detailed moisture maps in just 48 hours. The VSA charts nearly 200 data points to show exactly how your sample absorbs and desorbs water.

Predict, prevent, and understand moisture’s effects.

Isotherms are critical to understanding the moisture-related properties of chemicals, excipients and other ingredients. Many industries share open-access isotherm libraries – but the diversity of proprietary chemicals and excipients in the pharma industry mean there isn’t always reliable information available. With a VSA on the bench, researchers can build an infinitely valuable custom isotherm library in a matter of weeks.


Dynamic Vapor Sorption just got a big upgrade.

We call them Dynamic Dewpoint Isotherms, or DDI. While DVS waits for equilibrium at each new humidity level, DDI steadily pulses air over the sample, imitating humidity changes in the real world. DDI continuously measures changes in moisture content and water activity, producing isotherms 5x more detailed than DVS in a sixth of the time.

VSA stands alone. It’s the only analyzer with DDI technology – you won’t find absorption and desorption curves this detailed anywhere else.

With more than 100 points instead of five or six, the VSA’s DDI readings are detailed enough to pinpoint glass transition points. There’s no need to extrapolate anymore – it’s all in the isotherm. If an application calls for a lower resolution isotherm, the VSA easily switches into DVS mode.

Extract more insight from your data

The VSA comes with intuitive, full-featured modeling software complete with research-tested predictive models. The Moisture Analysis Toolkit will:

  • Help reduce and/or optimize excipients
  • Identify critical humidity for glass transition
  • Evaluate packaging performance
  • Determine hygroscopicity
  • Track hysteresis
  • Predict coating breakdown
  • Find susceptibility to caking/clumping
  • Plenty more
  • Accelerated shelf life studies, accelerated

    How will temperature, humidity, packaging, and moisture levels affect your product over time? Finding out doesn’t have to take months. Enter a few criteria, and the VSA’s powerful software will determine the minimum water vapor transmission rate your packaging needs in order to achieve the shelf life you’re aiming for.


    Technical specifications

    Measurement Specifications

    Isotherm Methods:
    • Dynamic Dew Point Isotherm (DDI) & Static (DVS)
    Water Activity
    • Accuracy : ±0.005 aw
    • Resolution: 0.0001 aw
    • Range: 0.030 to 0.950 aw @ 25 ◦C
    • Repeatability: ±0.003 aw
    • Temperature Control: 15 to 60 °C (sample chamber temperature; sample temperature is measured separately, and may vary)
    • Temp Stability : ±0.1 °C
    External Gas
    • 7 psi max
    Sample Weight Range
    • 500 to 5,000 mg
    Operating environment
    • 4 to 50 °C; 0 to 90% relative humidity (noncondensing)
    AROYA cultivation management base station

    Let’s talk applications.

    You don’t have to figure out how a new instrument fits into your workflow alone. We’re eager to hear your goals and discuss how we can help. Submit this form to talk to an expert.

    Masters of moisture.

    From cleansing irradiated Fukushima rice paddies to contributing to the discovery of moisture on Mars, we've solved complex problems in a long list of industries. More about METER →

    Wireless AROYA substrate soil moisture sensor with solar panel attached