SMS	Pros	Cons	Price
FDR	Accurate with soil-specific calibration (1% error) Can be used in saline soils High resolution signal Can be connected to conventional loggers Flexibility in probe design	Calibration is necessary Sensitive to soil temperature Small sensing area (3.2-inch diameter) Need for good contact between FDR and soil Sensitive to air gaps Sensitive to clay soils	60 - 300 per sensor 500 - 3,500 for data logger 2,000 - 3,000 for access tube installation kit
ADR	Accurate with soil-specific calibration (1% error) and without soil-specific calibration (5% error) Can be used in high saline soils Minimal soil disturbance Soil temperature does not interfere with signal	Calibration to a specific soil is recommended\nVolume of measurement is relatively small (≈ 0.3 in3)\nSensitive to air gaps, stones, or water traveling through channels separate from soil matrix	200 - 350 per sensor 1,000 - 3,500 for data logger
TDT	Accurate (2% error)\nLarge sensing volume (≈ 30 in3)\nLow power consumption	Sensitive to soil compaction Soil disturbance during installation Reduced precision because the generated pulse is distorted during transmission Needs to be permanently installed in the field	220 - 300 per sensor 1,000 - 3,500 for data logger