SMS	Pros	Cons	Price
GMS	Can measure a large area (8 - inch diameter) Can be used in moderately saline soils Can be used to sense wet or dry soil moisture readings for irrigation If soil does not dry out, little maintenance is required Good accuracy in medium to fine soils Data can be logged and retrieved remotely Applicable for large soil tension range Continuous measurement at same location Can be permanently installed (through winter) in soil No water refilling needed	Relatively inaccurate Performs poorly in sandy soils due to slow reaction time (water moves fast in sandy soils) Performs poorly in soils that shrink/swell Susceptible to drying; must be dug out and solution reset when this occurs Relatively slow response time to soil water changes Sensitive to soil temperature and high salinity Calibration in needed for each soil type Slow reaction time Does not work well in sandy soils	$40 - $70 per sensor\n250 for handheld metern500 -$600 for data logger
HDS	Sensor output is independent to electrical conductivity (EC) value. Measurements not affected by salts in the soil Small size Very accurate Soil/site calibration usually not required Remote access of data available Measures a wide range of matric potential Long lasting, with no maintenance required	HDS have a larger power requirement compared to other sensor types for frequent observations Very small area of influence Slow reaction time Does not work well in sandy soils	$280 - $380 per sensor\n$300 - $440 for excitation module\n$2,000 - $2,500 for data logger