Filtern
Dokumenttyp
Sprache
- Englisch (6) (entfernen)
Referierte Publikation
- nein (6)
Schlagworte
- VOC (3)
- Copiers (2)
- Dust (2)
- Emissions (2)
- Ozone (2)
- Printers (2)
- Air quality monitoring (1)
- Ammonia gas sensor (1)
- Blue Angel (1)
- Detection technology (1)
- Emission test chamber (1)
- Environmental label (1)
- Fluorescence (1)
- Gas detection (1)
- Gas storage sites (1)
- Hardcopy device (1)
- Hazardous and toxic gasses and vapours (1)
- Methane measuring (1)
- Miniaturized sensor device (1)
- Multi sensor device (1)
- Multi-gas sensor (1)
- Pump control (1)
- Quantification of gas concentrations (1)
- Selective permeability (1)
- Spatially distributed monitoring (1)
- Standard gas generator (1)
- Threats other than explosives (1)
- Warfare substances (1)
Because ammonia and its reaction products can cause considerable damage to human health and ecosystems, there is a need for reliably operating and reversibly interacting sensor materials to monitor traces of gaseous ammonia in ambient air, which at best can be used on-site for in-the-field measurements. Herein, the development of a sensor material for gaseous ammonia in the lower ppm to ppb range using optical fluorescence as transduction mechanism is presented. A fluorescent dye, which shows reversible fluorescence enhancement in the presence of ammonia is incorporated into a polymer matrix, the latter to ensure the accumulation of ammonia. The sensor material is integrated into a prototype of a miniaturized sensor device, facilitating long-term operation. To calibrate the optical sensor system a gas standard generator, producing standard gas mixtures, is used, leading to a sensitivity down to lower ppm concentrations of ammonia.
In preliminary work, gas sensors in linear form based on the measuring principle of gas selective permeability through a membrane were developed and introduced for the detection and quantification of gas concentrations. In this study, first experimental results are presented for adapting the technology for measuring methane (CH4). A material with suitable selective permeability was identified and utilized in a sensor setup containing the gas selective membrane and a reference membrane, both integrated in a measuring cell, to which a gas stream with defined CH4 concentrations was applied. The results prove the sensor's capability for measuring methane and indicate further application potential of the method, e.g., as a robust field monitoring technology, since CH4 is the major component of natural gas, town gas, and fracking gas.
This paper deals with the development and investi-gation of a volatile organic compound (VOC) system for differ-ent scenarios. The integrated multi-sensor unit can detect dif-ferent gases through the integrated 3-fold VOC sensor, where-by a continuous measurement takes place. The system-integrated flow control, with pump and flow sensor, allows the gas molecules to be transported directly to the VOC sensor. The entire measurement is permanently stored on an integrat-ed Secure Digital (SD) card. If the previously determined limit range is exceeded, an alarm is generated. Due to the combina-tion of different components, numerous applications are possi-ble. The system is the first step or a tool towards further devel-opments in the field of gas sensors and is primarily used for the validation of chemically based gas sensors, and it is still largely extended by application-specific influences.
Kurzfassung An neun verschiedenen Hardcopygeräten wurden in unterschiedlichen Emissionsmesskammern (zwei verschiedene 1 m³ - Kammern und eine 20 m³ - Kammer) in Kombination mit geeigneten Probenahme- und Analysenverfahren Untersuchungen zum Emissionsverhalten dieser Geräte hinsichtlich Staub, Ozon und VOC (TVOC) durchgeführt. Luftprobenahme und Analytik erfolgten für VOC mittels Tenax TA und anschließender Thermodesorption (TDS) in Verbindung mit GC / MS. Ozon wurde kontinuierlich bestimmt. Der Ozonanalysator arbeitete auf der Grundlage der flammenlosen Reaktion von Ozon mit Ethylen nach dem Prinzip der Chemilumineszenz. Die Staubbestimmung erfolgte gravimetrisch mittels Glasfaserfilter und Ultramikrowaage. Zusätzlich wurde die Partikelemission während des Druckbetriebes mit einem Partikelzähler bestimmt. Aufgrund der technischen Rahmenbedingungen standen nur kurze Druckzeiten von maximal 36 Minuten zur Verfügung. Um die Gleichgewichtskonzentration in der Prüfkammer zu erreichen, wurde die Luftaustauschrate in den 1 m³ - Kammern auf n = 4,0 bis 4,7 pro Stunde erhöht. Zusätzlich zur Prüfung in den Emissionsmesskammern sind verschiedene Papiere mittels Direkt - TDS sowie unter- schiedliche Toner mittels Headspaceprobenahme in Kombination mit GC / MS hinsichtlich ihres Emissionsverhaltens untersucht worden.
Für die untersuchten Geräte wurden Emissionsraten ermittelt. Sie betrugen für TVOC 0,41 bis 22,4 mg pro Stück und Stunde, für Ozon kleiner 0,02 bis 4,6 mg pro Stück und Stunde sowie für Staub 0,10 bis 7,63 mg pro Stück und Stunde. Verglichen mit Frischfaserpapier wurden bei den Untersuchungen mit Recyclingpapier deutlich höhere SVOC - Konzentrationen nachgewiesen. Im Ergebnis der Untersuchungen wurde ein Prüfverfahren entwickelt, das die Basis für Emissionsmessungen im Rahmen der Umweltzeichen RAL UZ 62, RAL UZ 85 sowie des neuen RAL UZ 114 für Multifunktionsgeräte darstellt. Abstract The emission behaviour with regard to dust, ozone and VOC (TVOC) of nine different hardcopy devices in combination with suitable air sampling and analysis procedures was investigated in different emission test chambers (two different 1 m³ - chambers and one 20 m³ - chamber). Air sampling and analysis for VOC were done by means of Tenax TA and subsequent thermal desorption (TDS) in connection with GC / MS. Ozone was determined continuously. The ozone analyser worked on the basis of the flame rid reaction of ozone with ethylene according to the principle of chemiluminescence. The dust determination was done gravimetrically by means of glass fibre filter and an ultra micro - balance. Additional the particle emission during the printing process was measured with a particle counter. The general technical conditions of the tested hardcopy devices were the reason for short printing times with a maximum of 36 minutes. In order to achieve the equilibrium concentration in the test chambers the air exchange rate in the 1 m³ - test chambers had to be increased to a value of n = 4,0 to 4,7 per hour. Additional to the examination of the hardcopy devices in the emission test chambers different papers were investi- gated by means of direct - TDS and different toners were tested by means of head space sampling in combination with GC / MS. For the examined hardcopy devices emission rates were determined. The emission rates for TVOC ranged from 0,41 to 22,4 mg per piece and hour, for ozone from less than 0,02 to 4,6 mg per piece and hour and for dust from 0,10 to 7,63 mg per piece and hour. The comparison between recycling paper and paper produced from primary fibres showed in general higher SVOC emissions from recycling paper. As the result of the investigations a test method for the determination of emissions from hardcopy devices was developed. This test method is the basis for emission tests in the framework of the German Award of the Environmental Label for office devices RAL -UZ 62, RAL -UZ 85 and the new RAL -UZ 114 for multifunctional devices.