FAQ for the Corneometer®
The Corneometer® measures in arbitrary units from 0 (no water at all) - 120 (on water). The units have been very wel establishes as so called "Conreometer units".
The penetration depth of the electric scatter field is demonstrably very small, so that only the moisture on the skin surface is measured. Measurements before and after covering a measuring area with a special foil (15 µm thickness) show that on the foil only 20 % of the original value are measured, the total measurement depth is approx. 40µm. This is important because especially the moisture content in the Stratum corneum is important for cosmetic applications.
Placing the probe head on the skin for several seconds may cause occlusion under the probe head (i.e. water is collected), thus increasing the moisture value. Also, it could be that the probe was not put straight onto the skin once or the pressure used on the probe was different. We recommend performing 3-5 measurements on adjacent areas and consider the average value. This also helps to minimize influences from artefacts (e.g. a single measurement on a hair, etc.).
The capacitance measurement of the Corneometer® is the worldwide most used hydration measurement. All other devices are only compared to the Corneometer®. Several hundreds of studies performed with the device prove this fact.
No, the capacitance measurement needs to have complete contact with the supporting surface. However a special Corneometer®-probe for hair is under development. Please contact us for further information.
The measuring principle is of course the same. With the current model we have only improved the sensitivity of the electronics to make the values of probe even more accurate and reproducible. In tendency the values are the same, but the results of the CM 285 are approx. 20 points lower than those of the CM 820. A multicentric study performed by the mayor German cosmetic companies and some independent testing laboratories in 2000 verified that both probes are measuring accurately the water content of the skin and are absolutely comparable (Source: U. Heinrich et al.: Multi Center Comparison of Skin Hydration in terms of physiacl -, physiological- and product-dependet parameters by the capacitive method (Corneometer CM 825), in International Journal of Cosmetic Science, 2003, 25, 45-53.)..