C - Lublin

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