Hortus - HMS-TDR Series - Time Domain Reflectometry (TDR) Monitoring Systems Brochure

Hortus srlHMS-TDRHMS-WEBHMS-HYDROHMS-METEOHMS-TDRHMS-GEOUnmanned system that manage TDR sensorsOverwiewTechnologyServicesAutomatic system using TDR (Time Domain Reflectometry) to monitor:• deep deformation in unstable slopes• soil moistureHMS-TDR stations are able to transmit data using GPRS and can be fully integrated with HMS-GEO and HMS-METEO series.Hortus offers specialist support to perform manual measures and data interpretation.HMS-TDR HMS-TDR HMS-TDR HMS-TDR HMS-TDR HMS-TDR HMS-TDR HMS-TDR HMS-TDR HMS-TDR HMS-TDR HMS-TDR HMS-TDR HMS-TDR HMS-TDR HMS-TDRHMS-TDR seriesTo customize your HMS-TDR system you can choose:• Installation: specialized assistance during installation in site.• Data interpretation: comparison of hystorical data set and analysis of results. • Web application: access to your data system from everywhere.Services for HMS-TDRData AcquisitionSystemThe monitoring of deformations in rock, or soil, using TDR technology is based on an indirect measurement method: the deformation itself is not measurement (as with an inclinometer), but is measured the change in impedance of a coaxial cable as a result of deformation, that is a directly dependent value.TDR can be described as “cable-based radar” and consists of two basic components: a combined transmitter/receiver (TDR cable tester) and a coaxial (or more) cable. TDR cable tester produces electric impulses, which are sent down the coaxial cable. When the pulses approach a deformed portion of the coaxial cable, an electric pulse is reflected and sent back to TDR cable tester; by measuring the time span between emission and reception of the signal, the distance between TDR cable tester and deformation can be determined.By analyzing the reflected pulse (its amplitude, width and form) can be obtained information about type and amount of deformation.For landslide monitoring, coaxial cable is installed into a borehole and connected to the rock with grout, or sand; there are three different installation methods:• coaxial cable is installed parallel to an inclinometer within the same borehole;• coaxial cable is installed into a sheared inclinometer casing, therefore extending the lifespan of an inclinometer borehole;• coaxial cable is installed into a borehole of its own, without inclinometer casing.TDR Cable tester has dual function: generates a very short rise time electromagnetic pulse that is applied to a coaxial system which includes a TDR probe (for soil water, or rock deformation, measurements) and samples and digitizes the resulting reflection waveform for analysis. To monitor soil characteristics it’s possible to use the elapsed travel time and pulse reflection amplitude, to determine soil volumetric water content, or soil bulk electrical conductivity. The specific probes act as a wave guide. Impedance along the rods varies with the dielectric permittivity of the surroundingsoil. Because the dielectric permittivity of soil primarily depends on the amount of water present, soil volumetric water content can be inferred from the reflected measurements; instead, soil bulk electrical conductivity is determined from the attenuation of the applied pulse.Usually, probes consist of three pointed rods and a rugged head.TDR probes are the sensors of the TDR soil moisture measurement and are inserted or buried in the medium to be measured. The probes are a wave guide extension on the end of coaxial cable. Reflections of the applied signal along the waveguide will occur where there are impedance changes. The impedance value is related to the geometrical configuration of the probe (size and spacing of rods) and also is inversely related to the dielectric constant of the surrounding material. A change in volumetric water content of the medium surrounding the probe causes a change in the dielectric constant. This is seen as a change in probe impedance which affects the shape of the reflection. The shape of the reflection contains information used to determine water contentand soil bulk electrical conductivity.Monitoring of soil moistureMonitoring of deep deformation in unstable slopes• Stainless steel IP66 enclosure, with welded stainless steel brackets for mounting to pole• Data acquisition system based on Campbell Scientific CR1000 with enhanced software programming and automatic GPRS transfer of data• SIERRA Wireless Xtend modem GSM/EDGE with GSM antenna• 60W photovoltaic power supply kit with stainless steel brackets for mounting to pole and 40Ah GEL battery• 24Vdc voltage regulator + CV120 relay module, to manage sensor supply• Automatic cable tester and cable multiplexer to manage different coaxial cables (or probes)+HMS-TDR systems can manage different components.DEEP DEFORMATIOn In UnSTAbLE SLOPES• Cable tester and coaxial cableSOIL MOISTURE• Cable tester and TDR probe• Soil temperature sensorTypical unmanned HMS-TDR systemAnalysis of TDR measurement for deep deformationAnalysis of deformation in unstable slopesvia Caboto 8/b 20025 Legnano (MI) - ItalyTel +39 0331 93.60.00 - Fax +39 0331 93.60.80e-Mail sales@hortus.it - www.hortus.itThanks to its experience in monitoring networks integration, since 2003 Hortus srl has designed, implemented, installed and maintained its own automatic environmental data acquisition systems (HMS-Series), based on Campbell Scientific data-logger, building the best technical solution for the customer’s needs.Being aware of the importance of having available data in real time, particularly during environmental crisis, like floods or landslides reactivation, our systems are equipped with redundant transmission system (standard IP using GPRS,WI-FI and Ethernet network, radio UHF, satellite connection).For data management, Hortus has designed a web platform that allows access, display and analysis of data from active monitoring systems. Hortus srl has more than twenty-year experience in the production of customized software for data acquisition and management collected by monitoring networks. The project of the first multi-protocol data acquisition installed in 1987 following landslide event of Val Pola, Valtellina, Italy. Since 1999 Hortus has dealt with the design, implementation and management of the web platform www.laghi.net, which is a recognized reference for the hydrological monitoring of the Italy’s northern region lakes.Environmental monitoring systemHortus srl