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Titel:
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Haalbaarheidsonderzoek: ontwikkeling van een ethanolsensor t.b.v. opslag van fruit
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Auteur(s):
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Gepubliceerd door:
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Publicatie datum:
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ECN
SF
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1-3-1999
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ECN publicatienummer:
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Publicatie type:
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ECN-C--99-020
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ECN rapport
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Aantal pagina's:
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Volledige tekst:
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25
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Download PDF
(234kB)
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Samenvatting:
The feasibility of low concentration (50 to 500 ppb) ethanol measurementswas investigated for use as control parameter in a patented 'Dynamic Control
System' (DCS) for cooled fruit and vegetable storing areas. The measurements
were carried out in two ways, directly in the gas phase, and at
concentrations to be found in the condensation water (circa 1 mM) of the
storage cells. Measurements in the liquid phase using a field effect
transistor (FET) in a pH-sensor-actuator, described elsewhere, have proved
that the possibilities of this method for ethanol determination are rather
limited. The pH sensor part of the device provides no suitable signal,
whereas the 'actuator' part of the device provides only an indirect
electrochemical signal. Owing to the indirect fashion of the signal, pursuing
this detection scheme would demand more research. This device could not
directly be tested with gas samples, presently it can only be used with
aqueous ethanol solutions. Solid Polymer Fuel Cell (SPFC) sensing devices
have been used to demonstrate the feasibility of ethanol measurements in
aqueous solutions and in gas phase. A home-made fuel cell was used for
measurements in aqueous solutions, whereas for gas-phase measurements a
modified version of a commercial breath testing apparatus (Lion Laboratories)
was used. The blanks and calibration lines indicated the suitability of the
modified breath test apparatus for low concentration gas-phase ethanol
determination. The effect of differences in the water vapor concentrations,
and the interference of other organic compounds present in cooled fruit and
vegetable storing areas have also been investigated
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