ekS - Instytut Agrofizyki im. Bohdana DobrzaÅskiego PAN w Lublinie ...
ekS - Instytut Agrofizyki im. Bohdana DobrzaÅskiego PAN w Lublinie ...
ekS - Instytut Agrofizyki im. Bohdana DobrzaÅskiego PAN w Lublinie ...
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6.1. Description of the laboratory setup<br />
Reflectometric measurements for the determination of the change of soil<br />
samples bulk dielectric permittivity with temperature, water content and electrical<br />
conductivity were performed using the setup presented in Fig. 18 and Fig. 19 and<br />
described in detail in Skierucha [81]. Below there is a short description of the<br />
measurement system.<br />
Fig. 18.<br />
The exper<strong>im</strong>ental setup for the determination of temperature effect on soil dielectric<br />
permittivity determined by TDR method<br />
The setup consists of three functional modules controlled by PC computer:<br />
− oscilloscope frame HP54120 with the TDR unit HP54121T,<br />
− self designed and manufactured interface connecting TDR probes to the<br />
TDR unit by eight position 0.01 - 2.4 GHz multiplexer [42], reading<br />
−<br />
selected temperature sensors and controlling the temperature chamber,<br />
temperature chamber consisting of a freezer, a fan-heater inside it and an<br />
additional fan to min<strong>im</strong>ize temperature gradients inside the chamber.<br />
PC compatible computer controlling the dedicated interface by means serial<br />
RS232C interface and the oscilloscope by universal GPIB interface, is connected<br />
to Internet to monitor the performance of the exper<strong>im</strong>ent in the remote way. The<br />
application software was written in Visual Basic to provide a user friendly<br />
interface for the operator. Temperature of the soil samples was controlled by<br />
switching on and off the fan-heater located at the bottom of the temperature<br />
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