C - Lublin
C - Lublin
C - Lublin
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The described setup worked several days measuring and transmitting the<br />
temperature data by the radio link. Totally there were 2772 radio connections with<br />
97% performed in the first attempt. Only 3% connections were repeated; 11 1-time,<br />
74 2-times and 1-time the attempt of radio connection had to be repeated 3 times to<br />
succeed. The readouts from the temperature sensors placed on various depths in the<br />
soil profile are presented in Fig. 2. As expected, the sensor that measured the<br />
ambient temperature had the shortest response time to the temperature change.<br />
The deeper the sensor was located, the slowest reaction on temperature change<br />
was observed. Additionally, reaction of sensors to the temperature change were<br />
shifted in time because of limited speed of temperature change in soil profile [5].<br />
SUMMARY<br />
The project of a modern monitoring system for the measurement of soil<br />
physical parameters is presented that is intended to be equipped with smart sensors<br />
and wireless communication in the ISM (Industrial, Scientific, Medical) frequency<br />
band 433 MHz. The system is designed on the base of advanced electronic circuits<br />
and its partial implementation in the form of two-point communication for the<br />
temperature measurement in a soil profile is presented. The study proves that the<br />
availability of advanced technology enables to enhance the existing measurement<br />
systems and sometimes only the sensors with functional and not expensive radio<br />
communication system for the remote control of measurement devices in the<br />
distance of several hundred meters. The developed hardware and software can be<br />
adapted to more complex monitoring systems working in compliance with IEEE<br />
1451 standard and covering larger areas including air-borne or satellite remote<br />
sensing and serve as a source for ground reference measurements.<br />
REFERENCES<br />
1. IEEE 1451 Web Site at http://ieee1451.nist.gov<br />
2. IEEE Std. 1451.2-1997, “IEEE Standard for Smart Transducer Interface for Sensors<br />
and Actuators – Transducer to Microprocessor Communication Protocols and<br />
Transducer Electronic Data Sheet (TEDS) Formats”, IEEE IMS, TC-9 Committee on<br />
Sensors Technology, IEEE, New York, N.Y., Sept.1998.<br />
3. nRF401-Single Chip RF Transceiver 433MHz, Revision: 1.6, Nordic VLSI ASA,<br />
www.nvlsi.no, February 2002.<br />
4. CC1000 Single Chip Very Low Power RF Transceiver, Chipcon, PRELIMINARY<br />
Datasheet (rev. 2.1), 2002-04-19.<br />
5. Walczak R.: Basic problems of mass and energy transfer in the soil-plant-atmosphere<br />
system. Zesz. Probl. Post. Nauk Roln., vol. 346, 12-22, 1987.<br />
129