Measure volumetric moisture content of soils and other material for scientific research, agriculture and civil engineering.
The MP406 has a reinforced body and stainless steel needles making it ideal for use in extreme environments such as mine sites, landfills and saline soils as well as standard agricultural soils. The quality manufacture of the MP406 leaves it with a lifespan of 20+ years in the most extreme environmental conditions.
The MP406 is the best sensor available for any serious researcher or scientist to measure accurately the moisture of soils in the field. Measurements are not affected by temperature or salinity. The MP406 can be used to take continuous measurements over time through permanent or temporary burial and connection to a soil moisture meter (SMM).
The MP406 is also used to measure the moisture content in materials used in mining, roadway and buildings. The material that can be measured by the MP406 is often soil but can be any composition of non-metallic powdered, liquid or solid substance into which the needles are inserted. It is especially suitable for mineral stock piles, mine tailings and sand for batch mixing of concrete.
The MP406 Soil Moisture Sensor can also measure soil water potential via the SMM Soil Moisture Meter and a soil water characteristic curve.
MP406 Soil Moisture Sensor Features
MP406 Soil Moisture Probe
|Measurement Range||0-100 VSW%|
|Accuracy||1% VSW% after calibration to a specific soil type
± 5 VSW% using the supplied soil calibration
|Response Time||Less than 0.5 seconds|
|Stabilisation Time||3 seconds approximately from power-up|
|Input Requirements||9-18 V DC unregulated|
|Power Consumption||24 mA typical, 30mA max|
|Output signal||0-1160mV for 0-100 VSW%|
|Total Length||210 mm|
|Needle Length||60 mm|
|Needle Seperation||12 mm|
|Needles||Stainless Steel (Grade 316) – does not corrode in saline solutions|
|Environment||Designed for permanent or temporary burial|
MP406 uses the standing wave principle of measurement. It is equivalent to a Time Domain Reflectometry (TDR) sensor without the need for a complex and expensive pulse generator. MP406 is a high accuracy, precision sensor with 1%VWC accuracy following soil-specific calibration and 0.01%VWC resolution.
The results from measurement of absolute volumetric soil water percent (VSW%) from prepared soil samples using the MP406 are given above (Figure 1). This result is typical of the results obtained from comparative testing of the MP406 in prepared soil samples, for a wide range of agricultural soils.
Standing Wave Technology and hence the MP406 are not affected by changes in temperature or salinity of the soil or material being measured and hence the values of VSW% are equivalent to oven dried water content.
The standing wave technique uses an oscillator to generate an electrical field in order to detect the dielectric properties of a substrate of interest. The parallel needles of an MP406 act as a coaxial transmission line to generate a signal. The amplitude of the signal is related to the dielectric constant which in turn is directly related to moisture content.
The results from measurement of absolute volumetric soil water percent (VSW%) from prepared soil samples using the MP406 are given alongside. This result is typical of the results obtained from comparative testing of the MP406 in prepared soil samples, for a wide range of agricultural soils. Standing Wave Technology and hence the MP406 are not affected by changes in temperature or salinity of the soil or material being measured and hence the values of VSW% are equivalent to oven dried water content.
Linearisation tables can be added to Data Loggers using the following data:
Converting Data Table for MP-406. From VSW% to mV & mA in mineral soil
|VSW%||mV MP406||mA MP406C|