Characterization Technology Overview: Technology Type: Electromagnetic Trade Name And/Or
Characterization Technology Overview:
Technology Type:
Electromagnetic
Trade Name and/or Model Number assigned by vendor:
EM31-MK2, EM34-3, EM34-3XL, EM38, EM39, EM16, EM61
Technology Scale: (Indicates the operational status of the technology.)
/ Pilot Scale - Available equipment is of sufficient size to verify technology feasibility or establish the design and operating conditions for a full-scale system. However, it is not of the size typically used for a commercially available system.
Vendor Services:
Information not provided.
Intended use of this technology.
Site Mapping
Physical Characterization
Equipment is:
Transportable Portable (hand-held)?
Patent Information
Registered trademark
Vendor has exclusive license
Patented
Patent Pending
Verification Program Information
/ This technology is being tested, or has been tested, in EPA SITE Emerging Technology Program.
/ This technology is in the Site Characterization and Monitoring Program.
Characterization Technology Description:
Describes the monitoring/measurement device or technology, including scientific principles on which the technology is based; whether full-scale system is continuous, on-demand, or single measurement; and whether the technology is transportable, portable, or in situ.
The Geonics Ground Conductivity Meters (GCM), such as the EM31-MK2, map geology or underground contaminant plumes by measuring terrain conductivity without electrodes or ground contact, using a patented electromagnetic inductive technique.
Surveys are readily carried out in all regions including those of high resistivity such as sand, gravel and bedrock. The EM31-MK2 provides two data sets describing two important properties of the earth; the Quadphase (conductivity) provides information on contaminant presence while the Inphase provides information on the presence of buried ferrous and non-ferrous metallic targets.
Operating under the same principles as the EM31-MK2, the EM34 is designed to achieve much greater depth of penetration and also yields much more information about the geo-electric section. The EM34-3 can be used at three intercoil spacings; 10, 20 and 40 meters. It may yield a depth of exploration of 7.5, 15, 30, and 60 meters thus having excellent abilities in plume reconnaissance and fracture detection.
Also based upon the same principles as the EM31-MK2, the EM38 is designed to be particularly useful for agricultural surveys for soil salinity. The EM38 has depths of exploration of 1.5 and 0.75 meters depending on the dipole orientation.
The EM39 provides measurement of the electrical conductivity of the soil and rock surrounding a borehole or monitoring well, using an inductive electromagnetic technique. The unit employs coaxial coil geometry with an intercoil spacing of 50 cm to provide a substantial radius of exploration into the host material while maintaining excellent vertical resolution; measurement is unaffected by conductive borehold fluid in the monitoring well or by the presence of plastic casing. The instrument operates to a depth of 500 meters.
The EM61, one of the newest instruments from GEONICS, is a time-domain metal detector which detects both ferrous and non-ferrous metals. A powerful transmitter generates a pulsed primary magnetic field in the earth, which induces eddy currents in nearby metallic objects. The eddy current decay produces a secondary magnetic field measured by the receiver coil.
The EM61 detects a single 200-letre (55 gallon) drum at a depth of over 3 meters beneath the instrument, yet is relatively insensitive to nearby cultural interference such as fences, buildings and power lines. The response is a single, sharply defined peak, greatly facilitating quick and accurate location of the target. Depth of the target can usually be estimated from the width of the response. The system can be pulled around as a trailer with odometer mounted onthe axle to trigger the data logger or it can be carried by a single operator with a shoulder harness.
The EM16 is the most widely used EM instrument of all time. It measures the local tilt ellipticity of very low frequency (VLF) broadcasts, and resolves these values into inphase and quadrature components of VLF response. The EM16 has discovered several base- and precious-metal orebodies, and many water-bearing faults.
The EM16R attaches to the EM16 and, using a pair of electrodes, measures the apparent resistivity of the earth. The TX27 is a portable VLF transmitter supplying a VLF field for surveying with the EM16/16R, if remote broadcasts are weak, intermittent or poorly coupled with the target. For EM16 surveys, the TX27 antenna consists of a long (1 km) grounded wire.
Characterization Technology Highlights:
Describes the key marketable features of the technology in terms of parameters measured, performance, implementation, or cost. Includes highlights such as monitoring niche and advantages over other technologies.
Information not available.
Limitations:
Describes the technical limitations, such as specific contaminants, site conditions, and waste preparation that could adversely affect applicability or performance.
Limited dynamic range (1-1000 mmhos per meter). At low values of terrain conductivity it becomes difficult to magnetically induce sufficient current in the ground to produce a detectable magnetic field at the receiver coil. Conversely at high values of conductivity-the quadrature component of the received magnetic field is no longer linearly proportional to terrain conductivity.
Setting and maintaining the instrument zero. Ideally in order to set the zero the instrument would be suspended in free space and the zero set there. The more acceptable alternative is to search out a region of very resistive ground, to accurately measure its conductivity using conventional techniques, and to set the instrumental zero at that location. This is the procedure which is actually followed.
It is necessary that this zero be accurately maintained over long period of time and over the wide variations of temperature encountered during geophysical survey in various parts of the world. This produces tight constraints on the circuitry, with the result that the zero may be in error by up to +/-0.2 mmhos per meter. Such an error would be negligible over the usual range of terrain conductivities; however in the event that measurements are being made on highly resistive ground the zero error can become significant.
Limited Vertical Sounding Capability. In theory it is possible to use a system such as the EM34-3 at a continuum of intercoil spacings to yield more information about electrical layering in the ground. To achieve a wide variety of inter-electrode spacings with conventional resistivity equipment is simple; in the case of the inductive electromagnetic technique the rapid fall-off of the magnetic field from the dipole transmitter introduces a serious dynamic range problem. In due course there will undoubtedly be instrumentation with a wider variety of spacings at the expense of additional complexity.
Other Comments:
Provides additional technology information, such as technology history, status, capabilities, experience, and applicable permits obtained (e.g., TSCA, RCRA).
Media Monitored or Characterized:
Actual - media on which this technology has been or is currently capable of being used.
Potential - media that this technology may be applied in the future.
/ / Soil (in situ)
/ / Sludge (does not include municipal sewage sludge)
/ / Solid (for example slag)
/ / Saturated sediment (in situ)
/ / Saturated sediment (ex situ)
/ / Groundwater (in situ)
/ / Dense nonaqueous phase liquids (DNAPL) [in situ]
/ / Light nonaqueous phase liquids (LNAPL) [in situ]
Monitoring Targets:
Actual - monitoring targets that have been monitored or characterized by this technology.
Potential - monitoring targets that this technology may be applied in the future.
/ / Buried Non Ferrous Materials
/ / Buried Ferrous Materials
/ / Conductivity
/ / Bedrock Stratigraphy
/ / Water Table
/ / Explosives/propellants
/ / Resisitivity
/ / Soil Types
/ / Soil Moisture
Waste Source or Site Types:
Actual - waste sources or site types on which this technology has been or is currently capable of being used.
Potential - waste source or site types that this technology may be applied in the future.
/ / Agriculture Applications
/ / Battery Recycling/Disposal
/ / Coal Gasification
/ / Dry Cleaners
/ / Gasoline Service Station/Petroleum Storage Facility
/ / Herbicide Manufacturing/Use
/ / Industrial Landfills
/ / Inorganic/Organic Pigments
/ / Metal Ore Mining and Smelting
/ / Municipal Landfills
/ / Munitions Manufacturing/Storage
/ / Paint/Ink Formulation/Use
/ / Pesticide Manufacturing/Use/Storage
/ / Petroleum Refining and Reuse
/ / Photographic Products
/ / Plastics Manufacturing
/ / Pulp and Paper Industry
/ / Other Organic Chemical Manufacturing/Use
/ / Other Inorganic Chemical Manufacturing/Use
/ / Semiconductor Manufacturing
/ / Uranium Mining
Technology Specifications
List of the components included with this system and the dimensions (how much space is needed for each component).
Entire unit / 24centimeter(s) / 20centimeter(s) / 3.66meter(s)(s) / 11kilogram(s)
Shipping requirements of this technology:
Power Requirements
This technology requires one of more of the following power supplies.
Batteries:
Time required before recharging or replacement:
Major Unit Process:
Technology Operation
Reagents/Supplies
Information not provided.
Reagents or supplies are sensitive to environmental conditions (that is, environmental controls such as refrigeration are required)?
Frequency of calibration required
Site specific - 1 field event (units)
Required sample preparation and perservation.
Information not provided.
Technology Maintenance
Maintenance
Routine maintanance
Information not provided.
Residual Wastes
Does this technology does not directly or indirectly produces residual wastes(hazardous or nonhazardous)? No
Are disposal costs associated with the wastes that are produced?
Health and Safety
What protective equipment or health and safety procedures are required to operate the technology?
Protective clothing
List any health and safety issues associated with the equipment.
Information not provided.
Permit Requirements
Are users of the technology required to obtain any federal or state permits, liscenses, or certifications for transporatiation, operation, or ownership of the technology? No
Technical Support
Is special training provided and/or required?
Information not provided.
Quality of technical support. (If an operator in in the field and the instrument breaks down or is not giving quality results, what kind of response can be expected?)
Cost Information
This Technology can be:
Purchased $ 550 - Total Cost
Leased $ 550 per week (avg) (units)
Equipment is not leased directly but information on third party sources can be provided.
Factors Affecting Unit Price.
Information not provided.
Other costs associated with this technology (for example, the cost of reagents if they are required and were not included in the cost informtion). Also indicated are the cost of refills or routinely required replacement parts.
Information not provided.
Technology Performance
Operating Conditions(tempurature, moisture, etc.)
Matrix and environment conditions that may interfere with the performance of this technology.
Matrix
Percent Organic Matter
Environmental Conditions
Information not provided.
Can this technology be operated successfully outside (i.e. a controlled environment is not necessary)? No
Data Type and Interpretation
This technology produces:
Qualitative (yes/no, absense or presense)
Quantitative (specific number)
Semi-Quantitative (measurement within range)
Data manipulation required time to obtain usable results:
Data must be entered into a software program that calculates or produced usable data.
Procedures and time requirements: Data converted into cencors maps and profiles.
Sample Throughput/Measurement Frequency - how long it takes to generate one useable data point. Throughput is measured by the total time required to obtain the data divided by the total number of data points.
NA
Development or Bench Scale Studies
Information not provided.
Estimated range of qualtity or size of targetmaterial needed to test the fesibility of this technology.
Information not provided.
Total number of bench-scale studies conducted on actual target materials from diffrent sources or sites. Studies pertaining to the same site once, regardless of the number of diffrent target materials.
0
Precision and Accuracy
Maximum measurement precision of the instrument.
0.1 percent (units)
Maximum measurement accuracy of the instrument.
5 percent at 20 mS/m (units)
Contaminant of Concern, Method of Detection Limit and Operational Range
Information not provided.
Literature and Techinical References:
Information not provided.
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