Cidlo vlhkosti pudy?

[Sudovec]

Co třeba Wikipedie a odkazovaná literatura? Taky nic?

TDR used in the Earth and Agricultural Sciences

TDR is used to determine soil moisture water content in porous media, where 
over the last two decades substantial advances have been made; including in 
soils, grains and food stuffs, and in sediments. The key to TDR’s success is 
its ability to accurately determine the permittivity (dielectric constant) 
of a material from wave propagation, and the fact that there is a strong 
relationship between the permittivity of a material and its water content, 
as demonstrated in the pioneering works of Hoekstra and Delaney (1974) and 
Topp et al. (1980). Recent reviews and reference work on the subject 
include, Topp and Reynolds (1998), Noborio (2001), Pettinellia et al. 
(2002), Topp and Ferre (2002) and Robinson et al. (2003). The TDR method is 
a transmission line technique, and determines an apparent TDR permittivity 
(Ka) from the travel time of an electromagnetic wave that propagates along a 
transmission line, usually two or more parallel metal rods embedded in a 
soil or sediment. TDR probes are usually between 10 and 30 cm in length and 
connected to the TDR via a coaxial cable.

http://en.wikipedia.org/wiki/Time-domain_reflectometer

----- Original Message ----- 
From: <novotny.pp@atlas.cz>
To: "hw" <hw-list@list.hw.cz>
Sent: Saturday, July 07, 2007 2:37 PM
Subject: Cidlo vlhkosti pudy?


Hledam navod na konstrukci nebo schema cidla vlhkomeru pro objemove mereni 
pudni vlhkosit, itealne metodou TDR (time domain reflectometry).

Dve hodiny googleni me neprivedlo k vysledku tak zkousim stesti tady.

Predem dekuji na nasmerovani.


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