Information Last Revised: 3/29/93
TTP Reference Number: RL-8503-PT
1. Technical Name of Technology: HaloSnif - Fiber Optic Spectrochemical Sensor
2. Common Name of Technology: HaloSnif
3. PI and Telephone No: Khris Olsen (509) 376-4114
4. Affiliation: Pacific Northwest Laboratory
5. Technology Category: Characterization and Monitoring
6. Developers: Pacific Northwest Laboratory
7. Application:
7.1. Where (in-situ/ex-situ): ex-situ
7.2. Media: air or gases
7.3. Targeted Contaminants: carbon tetrachloride, TCE, PCE, CFCs, any volatile chlorine containing compound
8. Scope of project (feasibility study, treatability, bench, pilot, field):
Field, laboratory, or work place
9. Integrated Demonstration (ID) Need/Requirements:
New technologies are needed to better characterize subsurface characteristics of geohydrological features and contaminant distribution for more cost-effective sampling strategies using remote, in situ or onsite field screening methods. These techniques will enable an improved understanding of subsurface variability by achieving high-density data acquisition, with high-resolution, and real-time processing instrumentation. The technology will provide low-cost data of site characteristics during characterization and cleanup, but also accurate and efficient monitoring during the long post-closure period.
The benefits of this technology include the reduction of long-term risk by improving the collection of data (quality, density, and frequency) which will enhance model prediction of the environmental consequences of waste disposal activities. Incorporating high density and frequency data into models may show that a particular site needs no remediation, thereby saving tens of thousands to millions of dollars.
Because of the sheer volume of samples sent to the laboratory for analysis, a reduction in the number of samples is required. Clearly, the development of new screening methods for use by field teams is needed to decrease the number of samples being sent to the laboratory and to prioritize these samples. HaloSnif offers many attractive features for real-time multipoint environmental field monitoring. These features include the small probe size, multiple probes with one central detection and data acquisition system, and the potential for fast response.
10. Objective
10.1. Objective of technology:
HaloSnif was originally designed to monitor carbon tetrachloride vapor at hazardous waste sites. It can detect any volatile chlorinated compound in air or gas. HaloSnif is classified as a real time compound class specific sensor. Therefore, it is valuable for monitoring at waste sites, chemical storage areas, or process-based manufacturing plants using CFCs.
10.2. Baseline (baseline technology to which it is compared):
Gas Chromatography with Purge and Trap (GC with P&T)
11. Process Description:
During monitoring operation, HaloSnif operating at sub-ambient pressure (40 torr) continuously draws an air sample through a critical orifice into the plasma excitation chamber where it is mixed with helium and excited with a radio-frequency signal inductively-coupled to the plasma chamber. The plasma chamber is coupled via a fused silica optical fiber to the signal processor unit. The optical emission of the plasma is filtered with an narrow band pass filter designed to monitor the 837.6 nm emission line from the excited chlorine atom. The intensity of the chlorine emission is directly proportional to the concentration of chlorine containing species in the sample gas. The detection sensitivity for carbon tetrachloride is 5 ppmv. The response of the system is linear from the detection limit to 10,000 ppmv. The detection limit for other containing compounds can be estimated by ratioing the percent of chlorine in the compound of interest to that of carbon tetrachloride.
Data acquisition is achieved using a LabView[TM] data acquisition software package mounted on a Macintosh computer system. The data acquisition system is interface to the electo-optical signal processing module via a 1 to 10 V analog output. Real-time concentrations of total chlorinated compounds are displayed on the monitor for observation by on-site personnel. All data is stored in computer memory for post-run processing and analysis.
11.1. Input:
Helium and a gas sampling line
11.2. Output:
HaloSnif is a monitoring technology. It provides information on the concentration of gas phase chlorine containing compounds in air or gas.
12. Summary of Technology Advantages (relative to the baseline: faster, better, cheaper, safer):
HaloSnif is a compound class specific sensor. There is no need to know which specific chlorine compound is present for HaloSnif to respond. HaloSnif's response is insensitive to moisture or other no chlorinated compounds present in the sample gas. Other advantages of HaloSnif include: response, reversibility, and operational range, as discussed below.
Instrument Response: HaloSnif is a real-time monitor responding immediately to the presence of chlorine-containing compounds. Equilibration times normally are less than 2 minutes to reach ninety percent of full scale.
Reversibility: HaloSnif's response is completely reversible when the source of chlorinated compound(s) is removed.
Range: HaloSnif's response to chlorinated species is linear from its detection limit of the compound (i.e., 4-5 ppm for CCl4) to approximately 10,000 ppm.
In addition, HaloSnif offers many attractive features for real-time multipoint environmental field monitoring. These include the small probe size, the ability to use multiple probes with one central detection and data acquisition system.
13. Limitations of Technology (relative to the baseline: faster, better, cheaper, safer):
a) HaloSnif's lower detection limits for most compounds ranges from 1-5 ppmv in air.
b) HaloSnif is not a compound specific sensor.
14. Major Technical Challenges:
No major technical challenges remaining prior to field implementation.
15. Technical Effectiveness:
15.1. Performance
15.1.1. Remaining Contamination: (contamination mobility reduction, volume reduction, toxicity reduction)
Summary (20 words or less): Not Applicable; HaloSnif is a monitoring technology.
Further Description (unlimited length):
15.1.2. Process Waste
15.1.2.1. Status of waste (mobility, volume, hazard, recyclability)
Summary (20 words or less): Not applicable
Further Description (unlimited length):
15.1.2.2. Treatment (needed, available)
Summary (20 words or less): None Required
Further Description (unlimited length):
15.1.2.3. Decontamination / Decommissioning
Summary (20 words or less): Not Applicable
Further Description (unlimited length):
15.1.2.4. Disposal (needed, available)
Summary (20 words or less): None Required
Further Description (unlimited length):
15.1.3. Practicality
15.1.3.1. Foreclose Future Options
Summary (20 words or less): Not Applicable
Further Description (unlimited length):
15.1.3.2. Reliability
Summary (20 words or less): The probes are well suited for continuous environmental monitoring over extended periods of time. This technology can operate 24 hours/day.
Further Description (unlimited length):
15.1.3.3. Failure Control
Summary (20 words or less): Routine maintenance will prevent premature system failure.
Further Description (unlimited length):
15.1.3.4. Ease of Use
Summary (20 words or less): HaloSnif in its present stage of development requires some general knowledge of optics and electronics for satisfactory operations.
Further Description (unlimited length):
15.1.3.5. Infrastructure
Summary (20 words or less): Not applicable
Further Description (unlimited length):
15.1.3.6. Versatility
Summary (20 words or less): The detector has great potential for monitoring applications for volatile chlorinated hydrocarbon compounds in soil gas or vadose-zone monitoring wells
Further Description (unlimited length): HaloSnif has the potential to detect gas phase compounds containing bromine, mercury, fluorine and possibly phosphorous by simply modifying the analytical emission wavelength monitored by the detector. The detector has great potential for environmental monitoring applications where spot measurements are required for volatile chlorinated hydrocarbon compounds in soil gas or vadose-zone monitoring wells. HaloSnif can be reconfigured as a element-specific detector for gas chromatography effluents containing chlorine- and fluorine-containing compounds. In addition, by simply replacing the critical orifice inlet with a open-face membrane material will allow HaloSnif to measure the concentration of total organic chlorine in water samples.
15.1.3.7. System Compatibility
Summary (20 words or less): HaloSnif provides a 0 to 10 volt analog signal output which is compatible with standard off-the-shelf software and hardware technology.
Further Description (unlimited length):
15.1.3.8. Off-the-Shelf (procurement ease)
Summary (20 words or less): All components of HaloSnif are commercially available. However, assembly is required.
Further Description (unlimited length):
15.1.3.9. Maintainability
Summary (20 words or less): This system should be relatively maintenance free in its final configuration.
Further Description (unlimited length): However, no field testing of the new compact unit has been conducted to determine its short term and long term maintenance requirements.
15.1.3.10. Safety Measures
Summary (20 words or less): Components used to construct this device are all considered intrinsically safe.
Further Description (unlimited length): RF emissions are not a health issue but some care is needed during operations of HaloSnif to prevent shock or burn hazards. No negative public safety and health impacts are anticipated. Proper procedures will be followed to minimize any worker exposure.
15.1.4. "Works" (functions as intended):
Summary (20 words or less): Recent testing a new commercial power supply unit indicates the system operates as designed.
Further Description (unlimited length):
15.2. Cost
15.2.1. Start-Up Cost
Summary (20 words or less): It is estimated that the final unit cost will be approximately $10,000 for the base system and approximately $250 per sensor assembly.
Further Description (unlimited length): HaloSnif is an assembly of non-capital (i.e., cost less than $5K) subsystems and parts.
15.2.2. Operations and Maintenance Cost
Summary (20 words or less): Operating and maintenance costs are expected to be minimal. However, extended operations (weeks or months) have not been preformed.
Further Description (unlimited length):
15.2.3. Life-cycle cost
Summary (20 words or less): HaloSnif technology has not matured so this can be estimated.
Further Description (unlimited length):
15.3. Time
15.3.1. Years Until Available
Summary (20 words or less): Approximately 2 years for full commercialization
Further Description (unlimited length):
15.3.2. Speed/Rate
Summary (20 words or less): Adequate funding should enable completion of initial commercialization with the specified time frame of 2 years for full commercialization
Further Description (unlimited length):
15.3.3. Years to Finish
Summary (20 words or less): Approximately 2 years
Further Description (unlimited length):
16. Environmental Safety and Health
16.1. Worker Safety
16.1.1. Exposure to Hazardous Materials/Hazards
Summary (20 words or less): Minimal risk from exposure to high voltage, radio frequency electrical signal.
Further Description (unlimited length):
16.1.2. Physical Requirements
Summary (20 words or less): HaloSnif requires approximately 4 square feet of bench space. Total system weigh approximately 50 lbs.
Further Description (unlimited length):
16.1.3. Number of People Required
Summary (20 words or less): Two person set up and one person to operate. Can also be set up for automatic operation.
Further Description (unlimited length):
16.2. Public Health and Safety
16.2.1. Accidents
Summary (20 words or less): Not Applicable
Further Description (unlimited length):
16.2.2. Routine Releases
Summary (20 words or less): 40 ml/min of helium
Further Description (unlimited length):
16.2.3. Transportation
Summary (20 words or less): Not Applicable
Further Description (unlimited length):
16.3. Environmental Impacts
16.3.1. Ecological Impacts
Summary (20 words or less): Not Applicable
Further Description (unlimited length):
16.3.2. Aesthetics
Summary (20 words or less): Not Applicable
Further Description (unlimited length):
16.3.3. Natural Resources
Summary (20 words or less): Not Applicable
Further Description (unlimited length):
16.3.4. Energy Demands
Summary (20 words or less): HaloSnif requires 5 amps of 110 VAC power to operate.
Further Description (unlimited length):
17. Socio-Political Interests
17.1. Public Perception
17.1.1. Proponent Reputation
Summary (20 words or less): Interested parties and individuals are unlikely to be familiar with this technology.
Further Description (unlimited length): The results of initial evaluations have been presented and published in professional journals and conference proceedings.
17.1.2. Familiarity / Understandability
Summary (20 words or less): Not Applicable
Further Description (unlimited length):
17.2. Tribal Rights / Future Land Use
17.2.1. Capacity for Unrestricted Use (terrestrial, aquatic)
Summary (20 words or less): Not Applicable
Further Description (unlimited length):
17.3. Socio-Economic Interests
17.3.1. Economic Impacts
Summary (20 words or less): Not Known at this time
Further Description (unlimited length):
17.3.2. Labor Force Demands
Summary (20 words or less): Not Known at this time
Further Description (unlimited length):
18. Regulatory Objectives
18.1. Compatibility with Cleanup Milestones
Summary (20 words or less): This technology has the potential to aid in achieving clean-up milestone related to RCRA and CERCLA activities.
Further Description (unlimited length):
18.2. Regulatory Infrastructure / Track Record
Summary (20 words or less): Not available
Further Description (unlimited length):
18.3. Regulatory Compliance
Summary (20 words or less): Not known at this time
Further Description (unlimited length):
19. Industrial Partnerships
19.1. Company Names:
Quanta Physik
19.2. Rationale:
Quanta Physik has successful provided PNL with a prototype power supply module. A second unit is expected by April, 1993.
19.3. Contract Mechanism:
Presently the two units constructed by Quanta Physik have been secured by standard purchase requisitions. Future transactions may be implemented through a licensing agreement.
19.4. Other Potential Companies:
A solicitation for transferring this technology for commercialization will be entered in Commerce Business Daily. Other potential markets where this technology could be applied are presently being investigated.
19.5. International:
20. Intellectual Property
20.1. Patent Ownership:
HaloSnif was developed at PNL. Patent has been assigned to PNL and DOE.
20.2. Other Owners:
None
20.3. Patent Number:
This technology is covered under U.S. patent 5,085,499, "Fiber Optics Spectrochemical Emission Sensors".
21. Cost Sharing:
Cost sharing may be of interest by industries which have specific monitoring needs. For example, monitoring of incinerator and facilities effluent monitoring. The system can also be adapted for use as an element selective gas chromatography detector for speciation of chlorine, fluorine, bromine and organic forms of mercury.
22. Background on this technology (Where did the idea come from? Who else is doing similar work? What have the results been to date? What is the most significant competitor to this technology?):
In 1985, Rice, D'Silva, and Fassel published a paper entitled "A New He Discharge-Afterglow and its Application as a Gas Chromatographic Detector." Concurrent with the Rice publication, DOE's Office of Fossil Energy (DOE/FE) was already supporting a program at PNL entitled "Multielement Detection of Gas Chromatography Effluents." The work by Rice suggested to PNL researchers that the RF excited detector may have several advantages over the standard microwave-induced helium plasma source being used at that time on the aforementioned DOE supported program. One specific advantage was the ability of the afterglow source to be more tolerant of contaminants in the plasma (i.e. chlorinated hydrocarbons or air). Because of the potential advantages of the afterglow source, a significant effort was made to characterize and improve the source. Two specific modifications were made to the original design: 1) axial viewing geometry and 2) operation of the source at less than atmospheric pressure (both modifications are reflected in the current configuration of HaloSnif). DOE/FE support for the microwave plasma program ended in FY 1987. In FY 1988, internal PNL funding was provided for "proof-of-concept" of a sensor specific for measuring the concentration of volatile organic compounds containing chlorine. A patent application was filed on September 2, 1988, based on the results of the Exploratory Research supported program for the halogen specific sensor using a radio-frequency induced helium plasma. Those results were also presented in a paper entitled "Fiber Optic Spectrochemical Emission Sensors" at the September 1988 SPIE meeting in Boston, MA. Internal PNL funding for HaloSnif continued into FY 1990. Funding was used at that time to modify and upgrade the system and to determine the response and behavior of the system to CCl4, a problem of particular importance in the subsurface environs of the Hanford 200 West Area. Results through FY 1990 were reported at the American Chemical Society's 199th National Meeting (April 22-27, 1990) in Boston MA and in an American Chemical Society Symposium Series "Element-Specific Chromatographic Detection by Atomic Emission Spectroscopy." During the latter part of FY 1991, HaloSnif funding was budgeted through the Characterizations System Integration Task (CSI), a DTT&E supported task. This funding was used to upgrade the system into a field portable unit for use at the Hanford Site. An important technical enhancement added at that time was the use of a high-efficiency, narrow-band interference filter for spectral analysis of the chlorine emission line in place of the much bulkier and more expensive dispersive spectrometer. Additional support in FY 1991 was provided by the US Air Force for a field demonstration at Tinker Air Force Base in Oklahoma City, Oklahoma and by the Savannah River VOC-NonArid Integrated Demonstration Project for measuring the TCE/PCE concentrations in vadose zone monitoring points and vapor extraction offgas. During FY 1992, a significant increase in funding was provided by CSI Task under the VOC-Arid Site Demonstration project. Comparable levels of support were also provided by the Tinker Air Force Base Innovative Demonstration Project and the Savannah River VOC-NonArid Site Integrated Demonstration Project in FY 1992. A final U.S. Patent was issued in February 1992. Technical enhancements developed during FY 1992 include the use of a background correction channel to provide a stable baseline, the testing of a membrane inlet system, and the addition of a computerized data logging system based on Labview software. Also in 1992 a commercial partner was identified interested in providing a power supply based on a inductively coupling plasma at much higher oscillator frequency (Quanta Physik, West Palm Beach, FL). Quanta Physik has also expressed interest in a licensing agreement for the production of HaloSnif. Plans in FY 93 call for identifying an industrial partner interested in commercialization of HaloSnif through a CRADA or licensing agreement. The only product competitive with HaloSnif is the Odyssey 20001-05, produced by Transducer Research, Inc. of Naperville, IL.
23. Reference Documents:
Griffin, J. W., Olsen, K. B.,Nelson, D. A., Matson, B. S., and Eschbach, P. A., 1988. "Fiber Optic Spectrochemical Emission Sensors". In the Proceedings of the SPIE 1988 Symposium. Boston, MA September 6-9, 1988.
Griffin, J. W., B. S. Matson, K. B. Olsen, T. C. Kiefer, and C. J. Flynn. 1989. "Fiber Optic Spectrochemical Emission Sensors: A Detector for Chlorinated and Fluorinated Compounds." >i>SPIE, September 5-8, 1989, Boston MA.
Olsen, K. B., J. W. Griffin, T. C. Kiefer, R. S. Matson, and C. J. Flynn. 1992. "A Fiber-Optic Spectrochemical Emission Sensor as a Detector for Volatile Chlorinated Compounds". ACS Symposium Series 479: Element Specific Chromatographic Detectors by Atomic Emission Spectroscopy; Ed. Peter C. Uden;
Anheier, NC, KB Olsen, and JW Griffin. "Fiber-Optic Spectrochemical Emission Sensor: A Detector for Volatile Chlorinated Compounds". Sensors and Actuators, in press.