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Submersible Spectrofluorometer for Real-Time Sensing of Water Quality.

Puiu A, Fiorani L, Menicucci I, Pistilli M, Lai A - Sensors (Basel) (2015)

Bottom Line: The elimination of filters and pumps has the advantage of greater system simplicity and especially of avoiding the risk of sample degradation.The obtained results are reported in the paper.The sensitivity achieved for chlorophyll-a detection was found to be at least 0.2 µg/L.

View Article: PubMed Central - PubMed

Affiliation: Diagnostics and Metrology Laboratory, ENEA, Via Enrico Fermi 45, 00044 Frascati, Italy. adriana.puiu@enea.it.

ABSTRACT
In this work, we present a newly developed submersible spectrofluorometer (patent pending) applied to real-time sensing of water quality, suitable for monitoring some important indicators of the ecological status of natural waters such as chlorophyll-a, oil and protein-like material. For the optomechanical realization of the apparatus, a novel conceptual design has been adopted in order to avoid filters and pumps while maintaining a high signal-to-noise ratio. The elimination of filters and pumps has the advantage of greater system simplicity and especially of avoiding the risk of sample degradation. The use of light-emitting diodes as an excitation source instead of Xe lamps or laser diodes helped save on size, weight, power consumption and costs. For sensor calibration we performed measurements on water samples with added chlorophyll prepared in the laboratory. The sensor functionality was tested during field campaigns conducted at Albano Lake in Latium Region of Italy as well as in the Herzliya Harbor, a few kilometers North East of Tel Aviv in Israel. The obtained results are reported in the paper. The sensitivity achieved for chlorophyll-a detection was found to be at least 0.2 µg/L.

No MeSH data available.


The water region observed by the spectrometer is illuminated by the UV and blue LEDs. Water and optoelectronic devices are separated by a quartz window (NHI-1191 by Helios Italquartz, Milan/Italy) with transmittance greater than 90%.
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sensors-15-14415-f002: The water region observed by the spectrometer is illuminated by the UV and blue LEDs. Water and optoelectronic devices are separated by a quartz window (NHI-1191 by Helios Italquartz, Milan/Italy) with transmittance greater than 90%.

Mentions: With the configuration reported in Figure 2, 2.4 mW of UV light (coming from 4 LEDs) and 1.12 W of blue light (coming from 2 LEDs) are delivered in the water region observed by the spectrometer. Laboratory tests showed that the sensitivity of the latter is so high that its charged-coupled device (CCD) is saturated by the tiny out-of-band LED emission. In order to avoid this effect, we filtered the LED emission. This approach reduces the emitted power but allows one to observe all the wavelengths below the cutoff wavelength. Keeping in mind that blue LEDs have relatively high power, a Semrock 447/60 BrightLine® Bandpass Filter, New York/USA (realized according to our specifications) was placed in front of each blue LED.


Submersible Spectrofluorometer for Real-Time Sensing of Water Quality.

Puiu A, Fiorani L, Menicucci I, Pistilli M, Lai A - Sensors (Basel) (2015)

The water region observed by the spectrometer is illuminated by the UV and blue LEDs. Water and optoelectronic devices are separated by a quartz window (NHI-1191 by Helios Italquartz, Milan/Italy) with transmittance greater than 90%.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4507635&req=5

sensors-15-14415-f002: The water region observed by the spectrometer is illuminated by the UV and blue LEDs. Water and optoelectronic devices are separated by a quartz window (NHI-1191 by Helios Italquartz, Milan/Italy) with transmittance greater than 90%.
Mentions: With the configuration reported in Figure 2, 2.4 mW of UV light (coming from 4 LEDs) and 1.12 W of blue light (coming from 2 LEDs) are delivered in the water region observed by the spectrometer. Laboratory tests showed that the sensitivity of the latter is so high that its charged-coupled device (CCD) is saturated by the tiny out-of-band LED emission. In order to avoid this effect, we filtered the LED emission. This approach reduces the emitted power but allows one to observe all the wavelengths below the cutoff wavelength. Keeping in mind that blue LEDs have relatively high power, a Semrock 447/60 BrightLine® Bandpass Filter, New York/USA (realized according to our specifications) was placed in front of each blue LED.

Bottom Line: The elimination of filters and pumps has the advantage of greater system simplicity and especially of avoiding the risk of sample degradation.The obtained results are reported in the paper.The sensitivity achieved for chlorophyll-a detection was found to be at least 0.2 µg/L.

View Article: PubMed Central - PubMed

Affiliation: Diagnostics and Metrology Laboratory, ENEA, Via Enrico Fermi 45, 00044 Frascati, Italy. adriana.puiu@enea.it.

ABSTRACT
In this work, we present a newly developed submersible spectrofluorometer (patent pending) applied to real-time sensing of water quality, suitable for monitoring some important indicators of the ecological status of natural waters such as chlorophyll-a, oil and protein-like material. For the optomechanical realization of the apparatus, a novel conceptual design has been adopted in order to avoid filters and pumps while maintaining a high signal-to-noise ratio. The elimination of filters and pumps has the advantage of greater system simplicity and especially of avoiding the risk of sample degradation. The use of light-emitting diodes as an excitation source instead of Xe lamps or laser diodes helped save on size, weight, power consumption and costs. For sensor calibration we performed measurements on water samples with added chlorophyll prepared in the laboratory. The sensor functionality was tested during field campaigns conducted at Albano Lake in Latium Region of Italy as well as in the Herzliya Harbor, a few kilometers North East of Tel Aviv in Israel. The obtained results are reported in the paper. The sensitivity achieved for chlorophyll-a detection was found to be at least 0.2 µg/L.

No MeSH data available.