The Corneometer® CM 825 is available as a stand-alone device, in the Derma Unit SSC 3, connectable to the MPA systems, or as a wireless probe (please see details in Basic Probe Systems).
The measurement is based on capacitance measurement of a dielectric medium, here the stratum corneum, the uppermost layer of the skin. With increasing hydration, its di-electric properties change. The measurement is based on the fact that water has a higher dielectric constant (81) than most other substances (mainly < 7).
Gold tracks on top of the in the probe head, separated from the skin by a glass lamina, build-up an electric field between the tracks with alternating attraction. One track builds up a surplus of electrons (minus charge) the other a lack of electrons (plus charge). When put on the skin surface, the scatter field penetrates the very first layer of the skin. The Corneometer® CM 825 measures the change in the dielectric constant due to skin surface hydration changing the capacitance of a precision capacitor. The measurement can detect even slightest changes in the hydration level. Unlike the impedance measurement no galvanic relation between the device and the measuring object and no polarization effects exists.
The hydration measurement is the basic measurement for all bio-medical and cosmetic applications.
Dimensions: 11 cm, Cable length: approx. 1.3 m, Measuring surface: 49 mm², Weight: 41 g
Measurement principle: capacitance, Units: arbitrary Corneometer® units, Measurement frequency: 0.9-1.2 MHz, Pressure: approx. 1.0 N ± 10 %, measurement uncertainty: ± 3%
For the technical data of the wireless probe, please see Basic Probe Systems.
Technical changes may be made without prior notice.