Post on 30-May-2020
Actual rain sensor dry out times compared to
estimated soil dry out times
Bernardo Cárdenas and Michael D. DukesAgricultural and Biological Engineering Dept.,
University of Florida
Urban Landscape SummitGainesville, FLMarch 21, 2019
Rain Sensor (RS)
•RS can bypass the timersettings, when therehas been sufficient rain.
Timer
Expanding Disks
OBJECTIVESa) Measure the dry out periods of 2 RSs
b) Estimate the dry out periods of 3 soil texturesthrough a soil water balance model (Wave)
c) Compare a) vs b)
MATERIALS AND METHODSLocation: On campus, UF,
Gainesville, FL
Data collection period:Jan 1 – Dec 31, 2007
Hunter RainClik
Receivers
Datalogger
Sensors/Emitters
Sensors/Emitters
ReceiversDatalogger
Toro TWRS
Weather Station
Tipping bucket
Data logger
(0.25 mm)
(m/d h:m:s)
Weather Station
Weather data
Inputs to Wave
WAVE to simulate hourly soil water balance
Clay Loam
Loam
Sand
RESULTS AND DISCUSSION
Standard error bars
CONCLUSIONS• The dry out periods of the tested RSs were shorter
than those of the different soil types modeled
• RSs: limited usefulness under Florida conditions
• An electronic mechanism that could delay thereturn of the RS to the allowing irrigation mode isrecommended
• This could greatly improve the functionality, watersaving potential, and acceptance of RSs
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Wireless RainClick
Expanding Disks
Antenna
Common
WaterValve
Timer
Hot
Common
WaterValve
Timer
Hot
QuestionDo the RS dry out periods match the soil dry outperiods?
WAVE to simulate hourly soil water balance
Time Rain(hh:mm) (mm)
18:00 1.519:00 0.320:00 0.321:00 1.322:00 1.323:00 1.3Total 5.8
Standard error bars
Standard error bars