Record Details

A low-power, low-cost soil-moisture sensor using dual-probe heat-pulse technique

DSpace at IIT Bombay

View Archive Info
 
 
Field Value
 
Title A low-power, low-cost soil-moisture sensor using dual-probe heat-pulse technique
 
Creator JORAPUR, N
PALAPARTHY, VS
SARIK, S
JOHN, J
BAGHINI, MS
ANANTHASURESH, GK
 
Subject WATER-CONTENT
CAPACITY SENSORS
CONDUCTIVITY
CONSTRUCTION
FIELD
Low-power DPHP sensor
Soil density
System design
Wireless communication
 
Description This paper presents the development and testing of an integrated low-power and low-cost dual-probe heat-pulse (DPHP) soil-moisture sensor in view of the electrical power consumed and affordability in developing countries. A DPHP sensor has two probes: a heater and a temperature sensor probe spaced 3 mm apart from the heater probe. Supply voltage of 3.3V is given to the heater-coil having resistance of 33 Omega power consumption of 330 mW, which is among the lowest in this category of sensors. The heater probe is 40 mm long with 2 mm diameter and hence is stiff enough to be inserted into the soil. The parametric finite element simulation study was performed to ensure that the maximum temperature rise is between 1 degrees C and 5 degrees C for wet and dry soils, respectively. The discrepancy between the simulation and experiment is less than 3.2%. The sensor was validated with white clay and tested with red soil samples to detect volumetric water-content ranging from 0% to 30%. The sensor element is integrated with low-power electronics for amplifying the output from thermocouple sensor and TelosB mote for wireless communication. A 3.7V lithium ion battery with capacity of 1150 mAh is used to power the system. The battery is charged by a 6V and 300 mA solar cell array. Readings were taken in 30 min intervals. The life-time of DPHP sensor node is around 3.6 days. The sensor, encased in 30 mm x 20 mm x 10 mm sized box, and integrated with electronics was tested independently in two separate laboratories for validating as well as investigating the dependence of the measurement of soil-moisture on the density of the soil. The difference in the readings while repeating the experiments was found out to be less than 0.01%. Furthermore, the effect of ambient temperature on the measurement of soil-moisture is studied experimentally and computationally. (C) 2015 Elsevier B.V. All rights reserved.
 
Publisher ELSEVIER SCIENCE SA
 
Date 2016-01-15T05:09:00Z
2016-01-15T05:09:00Z
2015
 
Type Article
 
Identifier SENSORS AND ACTUATORS A-PHYSICAL, 233,108-117
0924-4247
http://dx.doi.org/10.1016/j.sna.2015.06.026
http://dspace.library.iitb.ac.in/jspui/handle/100/17837
 
Language en