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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close vicinity of the analyzed object, which el<strong>im</strong>inates errors associated with the<br />
measured analog signal transmission along the wires. Now, the signal with the<br />
measurement results is digitally transmitted to the data processing unit (PC<br />
compatible computer or PIC16F874 interface) by means of the RS232C serial<br />
link.<br />
The temperature chamber is the specially adopted freezer. It has a heater and<br />
two vans installed inside, which ensure continuous air movement and<br />
min<strong>im</strong>ization of temperature gradient inside. Remotely activated heater in the<br />
temperature chamber creates the danger of non-controlled temperature increase<br />
and eventually fire. This may happen when for example the controlling program<br />
hangs-up for some reason when the heater is on. An independent temperature<br />
measurement system in the chamber protects the whole system against this<br />
danger. The protection has the upper temperature l<strong>im</strong>it set to the value which<br />
exceeded will reset the PIC16F874 microcontroller in the interface and set the<br />
digital outputs at PORT0, PORT1, PORT2 to the values corresponding to off state<br />
of the external devices, including the heater in the temperature chamber.<br />
6.2. Summary<br />
The presented system automatically registers data from the complex setup<br />
consisting not only on the data measurement devices but also actuators that<br />
control the measurement conditions. The applied hardware and software are<br />
applied for testing the temperature effect of physical parameters of the tested<br />
materials as well as the performance of the electronic devices. The system has<br />
been designed for the analysis of temperature effect on the soil dielectric<br />
permittivity. The results of this research are not the subject of the above study.<br />
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