Water is constantly evaporating from the skin which is part of the important body’s metabolism. The amount of water (Transepidermal Water Loss – TEWL) is expressed in g/h/m². As soon as the barrier function of the skin however is slightly damaged, the water loss will increase (even with smallest damages invisible to the human eye). Its measurement is an indispensable parameter for the evaluation of the water barrier function of the skin and a basic measurement in all kind of applications for topical applied products.
The C+K Tewameter® has always been working based on the “open chamber” measurement, a method which is acknowledged as the best way to asses this parameter*.
*E. Berardesca, M. Loden, J. Serup, P. Masson, L. Monteiro Rodrigues, The revised EEMCO guidance for the in vivo measurement of water in the skin, Skin Research Technology, 2018; 24: p. 351-358
The “open chamber” measurement method is the only method to assess the TEWL continuously without influencing its micro environment.
Inside the probe of the Tewameter® in a hollow cylinder, there are sensors to measure relative humidity and temperature.
The Tewameter® probe measures the density gradient of the water evaporation from the skin Δc which is proportional to the TEWL.
Where the predecessor model, the Tewameter® TM 300 had two pairs of sensor (for relative humidity and temperature) inside, the new Tewameter® TM Hex features thirty pairs of sensors which gives 15 x the information from before. The sensors are arranged in 6 columns with 5 sensor pairs each.
The name Hex acknowledges this fact, it is the Greek word for “Six”: „ἕξ“.
With this high amount of data for each single measurement and most modern electronics, the probe acts like a camera which “sees” the temperature and humidity distribution, thus giving extremely accurate, reproductive and quick results. Within seconds a robust TEWL value is measured with very low variation & measurement uncertainty.
Please watch a video on the revolutionary Tewameter® TM Hex.
Measurement uncertainty (Accuracy)
For the Tewameter® TM Hex for the time the measurement uncertainty (in g/h/m²) is recorded with each measurement value. This is a unique accuracy feature for a skin measurement tool and it is directly displayed with the robust TEWL in the table.
When you zoom into the TEWL curve, the measurement uncertainty for the whole curve becomes visible as a grey band around the measurement graph.
In addition, through this high data volume, we do not only have knowledge about what is measured inside the probe but can calculate results also for the areas right outside probe, namely skin surface and ambience above the probe.
Thus, the calculation of new, exciting parameters is possible which may give interesting insights in several research fields.