Performance of a Capacitance-Type Soil Water Probe in a Well-Drained Sandy Soil

Bandaranayake, Wije; Parsons, Lawrence R.; Borhan, Md. Saidul; Holeton, James

doi:10.2136/sssaj2006.0282

Cited by 12 publications

(20 citation statements)

References 6 publications

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“…1). This variation between sensors is not unique to this experiment and is commonly experienced by other researchers (Ould Mohamed et al, 1997;Chanzy et al, 1998;Seyfried and Murdock, 2001;Bandaranayake et al, 2007;Morel et al, 2008).…”

Section: Sensor Responsesupporting

confidence: 53%

Rapid procedure to calibrate EC-10 and EC-20 capacitance sensors in coir

Westhuizen

Rensburg

2013

WSA

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A rapid calibration procedure for EC-10 and EC-20 sensors is introduced to promote the commercial use of these sensors for hydroponic irrigation management in coir. The method is comprised of taking one sensor reading, by a sensor installed under hydroponic crop production conditions, and one gravimetric sample, both at field water capacity, to determine a correction factor for an accurate general laboratory calibration equation developed for coir. The rapid calibration procedure was evaluated by 4 separate sensors of EC-10 and EC-20. To verify the relative reliability of the rapid procedure, statistical analysis was performed separately for all data points and for data points between the drained upper limit and permanent wilting point of coir. From the statistical parameters used, it was observed that all of the predictions in the plant available water content range were good, with RMSE values < 0.030 m 3 •m -3 for the EC-10 and < 0.021 m 3 •m -3 for the EC-20 sensors. The D-index also pointed to a high accuracy of prediction in the plant available water content range, with values over 0.981 and 0.990 for the EC-10 and EC-20 sensors, respectively. Since a degree of variation remained between sensors, it was concluded that sensors should be calibrated individually. The rapid procedure proves a simple but scientifically sound method to calibrate sensors and is easy to apply to individual sensors in the field.

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Section: Sensor Responsesupporting

confidence: 53%

Rapid procedure to calibrate EC-10 and EC-20 capacitance sensors in coir

Westhuizen

Rensburg

2013

WSA

View full text Add to dashboard Cite

show abstract

“…Recent improvements to the ECH20 soil moisture sensor allowed for detailed measurement of soil water content (Sakaki et al 2008). The ECH2O EC-20, which offers a low cost alternative to other capacitance type meters, (Kizito et al 2008;Saito et al 2008;Sakaki et al 2008;Bandaranayake et al 2007;Nemali et al 2007;Plauborg et al 2005) has been used to improve irrigation management for citrus plantations (Borhan et al 2004). The precision of the ECH20 EC-20 is such that it can be used for greenhouse operations and to schedule field irrigation (Nemali et al 2007).…”

Section: Soil Moisture Measurementmentioning

confidence: 99%

“…EC-20 sensors allow for the determination of saturation, field capacity, and wilting point, along with the redistribution pattern of soil water, and possible drainage below the root zone. This information can be used to decide the time and amount of irrigation (Bandaranayake et al 2007). …”

Section: Soil Moisture Measurementmentioning

confidence: 99%

“…The overall length of the sensor is 8 inches with a width of 1.2 inches and blade thickness of 0.04 inches, with a 2.4 inch sensor head length. The total sampling volume of the probe is between 7.8 and 15.6 in 3 , depending on soil water content (Bandaranayake et al 2007). The ECH2O EC-20 soil probe measures the dielectric permittivity or capacitance of the surrounding soil medium, and the final output from the sensor is either in a millivolt or raw count value that can be converted to a volumetric water content using calibration equations (Kelleners et al 2005).…”

Section: Soil Moisture Measurementmentioning

confidence: 99%

“…Problems due to soil variation and air gaps can be avoided by using the factory installation tool and developing calibration equations relevant to each soil type. Drawbacks of this sensor include water leakage into the sensor circuit in isolated cases, and damage from animals such as gophers and squirrels (Bandaranayake et al 2007). Using the manufacturer provided equation, typical accuracy in medium textured soil is expected to be ±0.04 ft 3 /ft 3 (3% average error) with soil specific equations producing results with an accuracy of ±0.02 ft 3 /ft 3 (1% average error) (Decagon Devices, 2006b).…”

Section: Soil Moisture Measurementmentioning

confidence: 99%

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