Water Potential is a measure of the energy status of the water in a system. It is an indication of how tightly water is bound, structurally and chemically, within a substance. By using the Chilled-Mirror Dewpoint Technique, the WP4C measures the sum of the osmotic and matric potentials in a sample.

In soil applications, Water Potential is used to obtain moisture characteristics - this is useful for bioremediation, composting and fertilizer studies.

Water Potential is also an important parameter for seed samples (germination and priming) and in plant leaf applications.