We report on the design, fabrication and verification of a portable, low cost pid. Unlike commercial pid sensors, ours provides two outputs. One output correlates to the total chemical components and a second that pro...
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We report on the design, fabrication and verification of a portable, low cost pid. Unlike commercial pid sensors, ours provides two outputs. One output correlates to the total chemical components and a second that provides some level of compositional information. We believe that this makes this sensor system more useful than a standard commercial pid, at similar cost point. Our pid sensor was tested with gas concentrations down to 2 ppm isobutylene. The results presented indicate that the limit of detection will be well below 1 ppm. Compositional analysis was also carried out and the results presented shows our sensor can successfully discriminate between low concentrations of 2-hexanone, isobutylene, propanol, 2-pentanone, 2-octanone and 2-heptanone.
This paper describes the development and application of a multi-channel monitoring system for recording, processing, and analyzing volatile organic compound (VOC) levels discharged to the atmosphere from a walk-in hoo...
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This paper describes the development and application of a multi-channel monitoring system for recording, processing, and analyzing volatile organic compound (VOC) levels discharged to the atmosphere from a walk-in hood in a hazardous waste management facility. The monitoring system consists of an array of pid (photo ionization detector) sensors and a networked control program that provides operational schematic diagram, performs data analyses, and illustrates real-time graphical displays. Furthermore, the system records potential worker exposures, exhaust filtration efficiency and environmental release levels. Multi-channel continuous monitoring of VOCs is successfully implemented during chemical bulking operations. It is shown that a real-time monitoring system is effective for early warning detection of hazardous chemicals and for predicting the performance of adsorption filters used for VOC removal. In addition, a connected local weather visualization system supports efforts to minimize potential health and environmental impacts of VOC emissions to surrounding areas. (c) 2007 Elsevier B.V. All rights reserved.
In unauthorized areas, providing access to only authorized persons is a problem. The keyless entry eliminates the problems associated with the key duplication and break-ins but such a system has to be impeccable. Sinc...
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ISBN:
(纸本)9781467367257
In unauthorized areas, providing access to only authorized persons is a problem. The keyless entry eliminates the problems associated with the key duplication and break-ins but such a system has to be impeccable. Since the keyless security system works on batteries when operated as stand-alone system, a low power design is very much desired. In our approach, depending on the states of RFID and PIR sensor outputs, access is given only to authorized persons, whose RFID tag data matches with that of the program memory of FPGA. Further, the power saving is achieved in the place and route phase. Here, we make use of simulated annealing for placement and Lee maze router for routing. A comparison of initial and final placement is presented along with the power savings.
In air pollutant monitoring using sensors, moisture can adversely affect the analytical accuracy of volatile organic compounds (VOCs). Therefore, a new moisture pretreatment device (KPASS-Odor) for analyzing VOCs in t...
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In air pollutant monitoring using sensors, moisture can adversely affect the analytical accuracy of volatile organic compounds (VOCs). Therefore, a new moisture pretreatment device (KPASS-Odor) for analyzing VOCs in the air was developed, based on frost and created by a desublimation process inside a cold tube. The performance of KPASS-Odor was compared with conventional devices (i.e., a Nafion (TM) dryer and a cooler) through the measurements of low watersoluble VOCs (i.e., benzene, toluene, ethyl benzene, p-xylene, and styrene) and relatively high ones (i.e., methyl-ethyl ketone, methyl isobutyl ketone, butyl acetate, and isobutyl alcohol) using gas chromatography (GC) and sensor methods. Regarding the GC method, the recovery rates for KPASS-Odor and the cooler were >95% and >80%, respectively, at a flow rate of 500 mL/min for all compounds. For the Nafion (TM) dryer, the recovery rates differed between low and high water-soluble compounds, which exhibited the rates >= 88% and <= 86%, respectively. In terms of the sensor method, the VOC recovery rates of KPASS-Odor and the Nafion (TM) dryer were found to be >90% and <50%, respectively. Therefore, KPASS-Odor was determined to be the most suitable moisture pretreatment device for highly soluble VOCs of concern in this study.
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