Triple Probe Heat Pulse (TPHP) Soil Moisture Content and Temperature Monitoring Digital System Using Nanomaterials based Sensor Elements for Precision Agriculture

Abstract

I discuss the TPHP soil moisture content and temperature measuring digital system using Indium doped Tin Oxide nanopowder (ITO) electric heater and Nickel manganite (NiMn₂O₄) nanoceramic powder thermistor as a temperature sensor fabrication, characterization, calibration, and testing. The NiMn₂O₄ nanoceramic powder is synthesized using the wet chemical method and the ITO nanopowder-based heater is fabricated by a simple fill and press method. The heater, temperature sensor, Atmega328 microcontroller with its software, stainless steel cylindrical tubes, and 3D-printed package are used to fabricate the device. The distance between the heater and the temperature sensor is set to 0.006 m and heat pulse duration is set to 240 s. The heater consumes 3.587W electric power. The temperature sensor can measure the soil temperature up to 50°C. The system is capable of measuring volumetric soil moisture content from 3% to 37% efficiently with a strong correlation coefficient of $0.997$ with respect to the standard. The test result shows that there is less than a 2.8% error which is the smallest among the category and the sensitivity of the sensor at volumetric soil moisture content $({\theta }_v)=0.28{\text{m}}^3{\text{m}}^{-3}$ becomes ${3.14}^{\circ }\text{C}$ per ${\text{m}}^3{\text{m}}^{-3}$. The developed system is simple to fabricate and operate highly precise, low cost, low power and light in weight.

Keywords:

• NiMn₂O₄ nanoceramic powder
• Thermistor
• TPHP
• ITO
• Soil moisture

DISCLOSURE STATEMENT

No potential conflict of interest was reported by the author(s).

Additional information

Notes on contributors

Almaw Ayele Aniley

Almaw Ayele Aniley received PhD degree in electronics from Mangalore University, Mangalore, India in 2021 and Master of Technology degree in microelectronic engineering from Addis Ababa Institute of Technology, Addis Ababa, Ethiopia in 2011. Currently, he is working as assistant professor in Debre Markos University, Institute of Technology (IoT), School of Electrical and Computer Engineering, Debre Markos, Ethiopia. He has presented more than 14 research papers at national and international level and published 10 papers in reputed international journals, 2 book chapters and published 2 meeting abstracts. His research interest is nanosensors fabrication and characterization for different applications. He is also interested in artificial intelligence.