Zur Wärmeleitfähigkeits-Messung feuchter Stoffe bei beidseitig feuchtedichtem Probenabschluss

Thermal conductivity testing of damp sample material using double-sided moisture-proof end pieces.

Samples used for thermal conductivity measurements are normally dry. Using damp samples means that due to the temperature gradient generated, not only will a temperature-field over the entire sample cross-section build up, but also there is no way to avoid moisture transfer inside the sample; even with both surfaces considered moisture-proof. The sample will not pass moisture over the surface during measurement, but the moisture inside the sample could shift causing release or absorption of latent energy. This would generate an impact on the temperature field during measurement. The moisture flow is characterized by the so called 'moisture influence factor', which has been monitored in a former test, using a one-sided moisture-proof end piece. The samples with double-sided moisture-proof end pieces used in the current test series show nearly identical 'moisture influence factors'. This result is surprising and seems to prove that the influence of the existing hydric boundary conditions (one-sided or double-sided moisture-proof end piece) is much less than previously assumed.