The Auto-RH system is a modular bench-top system for automated control of relative humidity (RH) between ~1% RH and 95% RH. Corresponding range of total suction control is ~600 MPa to ~7 MPa. The system may be used for conducting suction-controlled tests in unsaturated soil mechanics applications, including determination of the soil-water characteristic curve (SWCC) in the high suction range, suction-controlled strength tests (e.g., triaxial, direct shear), or suction-controlled volume change tests. The Auto-RH system has several advantages over other common methods for controlling RH (e.g., osmotic or salt solution methods): Specific values of RH can be targeted automatically and approached along either wetting or drying paths. The forced-flow nature of the system significantly reduces equilibrium time. Automated RH control is insensitive to temperature fluctuations.
- Produces humid gas stream at a user defined flow rate
- Automatic algorithm to target and maintain humidity.
- Humidity control along wetting or drying paths
- Integrated high-precision RH/Temperature probe
- Software with interface for automated data acquisition and control
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