Transepidermal water loss (TEWL)
Water evaporates from the surface of the skin all the time, which states part of the human body’s metabolism. The evaporation rate of water from the skin surface is expressed in g/h/m^2. The Tewameter TM Hex probe, a direct successor to the well-known Tewameter TM 300 probe, is used to accurately measure water loss through the skin surface.
Operating principle
The most common method of measuring water loss is through an “open chamber.” It is used because the measurement itself has no effect on the rate of water loss.
There are 30 pairs of temperature and humidity sensors inside the Tewameter TM Hex chamber. Water loss calculations can be calculated based on the change in relative humidity and temperature with distance from the skin surface once steady state is reached.
Advantages
- fast, and accurate measurement thanks to 30 pairs of sensors
- reaching steady state after just 20 seconds
- sensor placed sibetrically, in 5 layers and 6 columns
- possibility of using disposable casings
- cooperation with MPA CTplus software
- Possibility of cooperation with the ambient conditions sensor RTH 400
Technical data
| Height of the measuring chamber | 2 cm |
| Diameter of the measuring chamber | 1 cm |
| Probe length | 17 cm |
| Cable length | 1.3 m |
| Weight (with cable) | 75 g |
| Measurement principle | Open chamber |
| Number of sensors | 30 pairs |
| Calibration and offset control | embedded |
| Repeatability of measurement (range 99%) | ± (0.15 g/h/m² + 1.0 %) |
| Measurement uncertainty (max.) | ± (0.5 g/h/m² + 5.0 %) |
| Working conditions | T: 10-40° C, RH: 30-70 % RH |
