Progress 09/01/20 to 08/31/23
Outputs
Target Audience:Our effort is geared toward the firefighter and emergency responder community, as well as health professionals and the public in general. Our efforts to develop inexpensive, reliable air quality monitors for wildfire safety applications will result in devices that may be used in a variety of outdoor and indoor applications. We are currently working with partners who are interestested in a range of applications - from indoor air and ventilation control, ambient outdoor air quality in rural andsmaller farmers and urban areas, to vineyard owners for protecting the health of the workers as well as the quality of the crops. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?* This project provided the opportunity for our engineering staff to gain expertise in 3D CAD and 3D printing of prototype parts and cases * The project also provided experience in integrating data from multiple wireless devices into a cloud database and user "dashboard" development. * The project provided opportunities for the electrical engineers to gain experience in ultra-low power electronic design as well as "machine learning". How have the results been disseminated to communities of interest?We have been talking directly with potential end users (firefighters, "data as a service" providers, and agricultural researchers. We have presented results at several conferences and published one journal articleto date. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
The initial prototype monitor includes sensors for particulate, CO2, VOCs, and toxic gases including CO, NO2, SO2, and ozone. We integrated the KWJ CO, NO2, SO2 and ozone gas sensors, plus Sensirion's SCD30 CO2 and SPS30 PM sensors, with necessary electronics into a single package. The objective for lowest cost and power is to reduce the number of continuously powered sensors to the minimum needed for definite detection and monitoring of a wildfire. Ideally, one or two of the electrochemical sensors will provide definitive alerts of possible fires, which will then increase the sampling rate of the PM - and possibly VOC sensor - for confirmation. During Year 1 of the Phase II we evaluated emission data from simulated fires both in-house and data obtained thru our collaboration with Thingy, LLC and the US EPA using a variety of wildland fuels. During Years 2 and 3, the sensors - including improved CO and SO2 sensors from SPEC - were deployed outdoors, and pollutant levels monitored in several locations over a 1 year period.Emission data from nearby wildland fires indicate strong correlation between
Publications
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2023
Citation:
https://www.morressier.com/o/event/63c18f0aeea665001900c0a6/article/642afd9624492a00128e8b6b?contentLibrary=ACS&contentLibraryTitle=American+Chemical+Society&from=%2Flibrary%2FACS
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2023
Citation:
SMSI 2023, Nuremberg, Germany, Poster,
https://www.ama-science.org/proceedings/details/4474
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2023
Citation:
ISES 2023, Chicago, Poster (August 27-31, 2023)
|
Progress 09/01/20 to 08/31/21
Outputs
Target Audience:Our effort is geared toward the firefighter and emergency responder community, as well as health professionals and the public in general. Our efforts to develop inexpensive, reliable air quality monitors for wildfire safety applications will result in devices that may be used in a variety of outdoor and indoor applications. We are currently working with partners who are interestested in a range of applications - from indoor air and ventilation control, ambient outdoor air quality in rural and smaller urban areas, to farmers and vineyard owners for protecting the health of the workers as well a the quality of the crops. Changes/Problems:Several circumstances have contributed to some delays in the project,with a corresponding reduced effort being charged to the project in Year 1.We have, however, develop approaches to mitigate theses issues, and are in position to add the necessary effort to keep the project on track for field evaluationof prototypes Spring-Summer 2022. Continued necessity for remote working, travel restrictions and material unavailability due to continued COVID are having some impact on the needed hands-on collaboration, requiring coordination and shipping of materials between locations. We have implemented weekly web meetings for the entire team, with in person meeting and telecons between the technical team members as needed. There is a severelack of availability of some of the specialized electronic components, combined with tremendously increased pricing for the limited quantities that can be found. For example, the digital potentiostat chip which is the heart of the SPEC DGS module has increased from a manufacturer's price of <$2 to spot prices of >=$100! It appears that this is due to a combination of reduced production by manufacturers, as well as apparent hoarding/marking up by 2nd-party resellers. As discussed earlier, KWJ is working with SPEC sensors to develop an alternative potentiostat of comparable performance using discrete components. We are still awaiting receipt of two fully outfitted AQ monitors and gateways from our partner, shipping is delayed due to availability of electronic components. These shortages and tremendous cost increases are impacting both our ability to get components needed to build the prototype monitors, but also potentially impacting the end cost of the monitor and our goal of introducing a much more affordable air quality monitor for firefighter safety and distributed air quality monitoring. Our engineers are looking at alternative chips such as the Analog Devices potentiostat which, though more expensive, seem to be more readily available. We are also evaluating the time and effort needed to redesign the circuitry using discrete components. This would be a safer path, relying less on very specific components, but will result in bulkier, less flexible circuits, likely causing us to need multiple versions of the boards rather than the single board with programmable bias, gain, etc., that is possible with the newer integrated digital components. What opportunities for training and professional development has the project provided? This project is providing the opportunity for our engineering staff to gain expertise in 3D CAD and #Dd priniting of protoype parts and cases The project is also providing experience in integrating data from multiple wireless devices into a cloud database and user "dashboard" development. How have the results been disseminated to communities of interest?We have been talking directly with potential end users (firefighters, "data as a service" providers, and agricultural researchers. We have presented results at one conference and submitted one article for publication to date. What do you plan to do during the next reporting period to accomplish the goals?Long-term testing of Field Units Deployed Outdoors: Beginning Fall of 2021, we plan to have 3-4 monitors deployed outdoors in the SF Bay area - 2 in Newark, 1 in Livermore, and a 4th located at various locations, coordinating with the local fire departments during prescribed burns. These monitors will be a combination of the KWJ prototypes (both 5-gas and 2-gas plus PM) and the commercial field versions we are jointly developing with Thingy, LLC, our initial commercial partner. We plan to collect ambient data for several months over the winter and spring, during periods of low wildfire occurrence. The monitors will be located as close as possible to an EPA or Bay Area Air Quality Mgmt. District (BAAQMD) air quality monitoring station. Design of Alternative electronics for the electrochemcial sensors: Due to the extreme shortage of chips and other electronic integrated components caused tothe manufacturing supply-chains by the COVID pandemic, several key components of the SPEC Sensors DGS digital potentiostat are back ordered by the vendor for 9-12 months. Available quantities of these components are being sold by resellers at costs 50-100X the manufacturer's list price. KWJ is going to evaluate alternative circuit designs, using more standard, discrete components. This unanticipated effort will done in parallel with continued evaluation of monitors using SPEC DGS modules we had already purchased. Gas Sensor Evaluation and Improvement: KWJ Engineering's primary technical strength is in the area of gas sensors - design, engineering and application. By partnering with SPEC sensors for sensor manufacture, and partners like Thingy, LLC to provide the telecommunications, networking, and embedded hardware expertise, KWJ can focus on sensor improvement and package design to get the highest performance possible from low-cost, near-zero power gas sensors. With the improvements in S/N and lower detection limit, we are observing new limitations to the accuracy of the SPEC gas sensors. Two issues which are potential hurdles for accurate detection at low ppb-levels are temperature effect on the zero current, and cross-sensitivity of pollutants present in higher concentrations on a given sensor. Zero Temperature Coefficient (ZTC): We plan to acquire sets of SPEC sensors from multiple build dates and evaluate the magnitude and uniformity of the ZTC across multiple sensors and batches. Ideally, the ZTC should be as ssmall as possible, practically we are working with SPEC sensors to improve the uniformity of the ZTC to allow standard compensation coefficients rather than having to perform a multi-temperature zero calibration for every sensor. Cross-sensitivity: for trace gases including SO2, O3 and NO2, which are typically present in low ppb levels - and health effects are of concern below 100ppb - it is important to have the highest selectivity possible, with minimal interfering components. We have observed ~1-2% cross-sensitivity to CO by the SO2 sensor, corresponding to 10-20ppb equivalent response to a 1ppm CO level. We have also observed diurnal response on both the O3 and NO2 sensors when placed outdoors. These response appears to correlate with other parameters including temperature, CO level, and VOCs. CO and temperature have been eliminated as possible causes by testing each parameter individually in the laboratory. NO has also been discounted as the response is observed even while NO is undetected by the reference analyzer. Laboratory work will include investigating interferences and other possible causes of baseline shift, including other oxides of nitrogen and common outdoor VOCs - which are generated by traffic, industry, combustion of fuels as well as wildfires. Fabrication, Test and Evaluation of Electrostatic UF PM Sensor: KWJ will continue the work with Ga Tech and the University of MN to iterate the design of the MEMS resonator mass sensor. Dr. Hesketh's team at Ga Tech hasmodelled the resonator, and based on the initial results obtained with the first iteration over the summer of 2021, are evaluating design modifications. Based upon the results of the evaluation of the 1st prototype, a second prototype with adjusted dimensions will be manufactured and tested for funtionality at Ga Tech and the Univ of MN. Dr. Hogan's Team at the Univ of MN Aerosol Laboratory will provide design input and conduct performance testing of the structures once fabricated. Samples of the second prototype with adjusted dimensions will be provided to Dr Hogan's laboratory, for a full evaluation of performance.Subsequent to response function determination and charge distribution measurement, we will be able to understand the limits of the detection of the BAR?integrated electrostatic classifier. We will also be able to define how a combined plasma ionizer?electrostatic classifier should be operating in field settings, as well as the optimum manner to describe size distributions with it (i.e. as the instrument only has three or four channels, we will seek to apply a simplified data inversion routine to determine approximate particle mass concentrations in 4 different size bins). UMN will carry out intercomparison studies of the electrostatic classifier system to a conventional DMA?condensation particle counter system, operated as an SMPS.
Impacts
What was accomplished under these goals?
The initial prototype monitor includes sensors for particulate, CO2, VOCs, and toxic gases including CO, NO2, SO2, and ozone. We integrated the KWJ CO, NO2, SO2 and ozone gas sensors, plus Sensirion's SCD30 CO2 and SPS30 PM sensors, with necessary electronics into a single package. The objective for lowest cost and power is to reduce the number of continuously powered sensors to the minimum needed for definite detection and monitoring of a wildfire. Ideally, one or two of the electrochemical sensors will provide definitive alerts of possible fires, which will then increase the sampling rate of the PM - and possibly VOC sensor - for confirmation. During Year 1 of the Phase II we evaluated emission data from simulated fires both in-house and data obtained thru our collaboration with Thingy, LLC and the US EPA using a variety of wildland fuels. Research Findings or Results: Emission data from fires indicate strong correlation between
Publications
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2021
Citation:
18th IMCS 2021 Meeting, May 30 â¿¿ June 3rd 2021: â¿¿Ultralow Power Sensor Package for Early Warning of Wildland Fires,â¿ Joseph R Stetter, M. W. Findlay, D. Peaslee, Scott Waller and Andrew Smallridge
- Type:
Journal Articles
Status:
Awaiting Publication
Year Published:
2021
Citation:
â¿¿Distributed Sensors for Wildfire Early Warnings,â¿ M. Findlay, D. Peaslee, J.Stetter, Scott Waller, and Andrew Smallridge; Journal of the Electrochemical Society
|