Sorption Hysteresis: Wetting and Drying Paths Can Differ

Identify the Material Response

Surface Measurement Systems describes sorption hysteresis as different uptake on adsorption and desorption paths. Its discussion includes multiple possible mechanisms, so the loop alone does not identify one physical cause. Primary reference: sorption hysteresis.

Review a Hypothetical Comparison

Imagine an invented sample at the same temperature and 50 percent relative humidity: the recorded equilibrium mass is 101 g on the increasing-humidity path and 103 g on the decreasing path, relative to a 100 g reference. The two-point difference is 2 g. Averaging them to 102 g would hide the path distinction.

Keep the Evidence with the Decision

Plot both directions with their previous exposure, step duration and stated equilibrium endpoint. Keep the initial reference and any irreversible change visible. Ask whether the criterion actually establishes the intended equilibrium observation; a still-changing sample can produce a kinetic difference that requires separate interpretation from the claimed equilibrium loop.

A loop is not automatically evidence of delayed measurement, nor does it establish one pore structure or phase transition. Preserve the material and path evidence before choosing a mechanistic explanation. The fictional masses give no adsorption model, humidity limit or HM filling specification. Their purpose is to show why one reported uptake value should retain the route by which that state was reached.

Which moisture history belongs to the reported equilibrium relation?

This blank worksheet is for your own project. It contains no H M machine trial result.

Customer Questions

Primary References

These references support the technical principles discussed in this guide. The worked examples and review questions are educational.

• Primary reference: sorption hysteresis
• Reference from hmpharmamachines.com