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Formaldehyde gas sensors: a review.

Chung PR, Tzeng CT, Ke MT, Lee CY - Sensors (Basel) (2013)

Bottom Line: Accordingly, the emergence of sophisticated technologies in recent years has prompted the development of many microscale gaseous formaldehyde detection systems.Besides their compact size, such devices have many other advantages over their macroscale counterparts, including a real-time response, a more straightforward operation, lower power consumption, and the potential for low-cost batch production.This paper commences by providing a high level overview of the formaldehyde gas sensing field and then describes some of the more significant real-time sensors presented in the literature over the past 10 years or so.

View Article: PubMed Central - PubMed

Affiliation: Department of Architecture, National Cheng Kung University, Tainan 701, Taiwan. benjamin@archilife.ncku.edu.tw

ABSTRACT
Many methods based on spectrophotometric, fluorometric, piezoresistive, amperometric or conductive measurements have been proposed for detecting the concentration of formaldehyde in air. However, conventional formaldehyde measurement systems are bulky and expensive and require the services of highly-trained operators. Accordingly, the emergence of sophisticated technologies in recent years has prompted the development of many microscale gaseous formaldehyde detection systems. Besides their compact size, such devices have many other advantages over their macroscale counterparts, including a real-time response, a more straightforward operation, lower power consumption, and the potential for low-cost batch production. This paper commences by providing a high level overview of the formaldehyde gas sensing field and then describes some of the more significant real-time sensors presented in the literature over the past 10 years or so.

No MeSH data available.


(a) Schematic illustration of formaldehyde sensor based on photometer and reagent-filled filter. (b) Variation of sensor response with formaldehyde concentration given sampling times of 1, 3 and 5 min [5].
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f5-sensors-13-04468: (a) Schematic illustration of formaldehyde sensor based on photometer and reagent-filled filter. (b) Variation of sensor response with formaldehyde concentration given sampling times of 1, 3 and 5 min [5].

Mentions: The instrument (Figure 4(b)) detected the surface color change of the detection tablet from white to yellow, which was monitored as a function of the intensity of the reflected light illuminated by an LED (475 nm). The response was proportional to the formaldehyde concentration. Kawamura et al. [5] proposed a hand-held formaldehyde gas sensor comprising an LED light source (wavelength 540 nm) and a circular filter impregnated with potassium hydroxide solution and 100 μL of 4-amino hydrazine-5-mercapto-1,2,4-triazole (AHMT, see Figure 5(a)). When the filter was exposed to formaldehyde gas, the AHMT reagent reacted with the HCHO and resulted in a change in the color of the filter. The color change was then recorded by measuring the intensity of the light reflected from the surface of the filter using a photodiode. The results showed that a minimum detection limit of 0.04 ppm HCHO was possible given a sampling time of 3 min or more (see Figure 5(b)).


Formaldehyde gas sensors: a review.

Chung PR, Tzeng CT, Ke MT, Lee CY - Sensors (Basel) (2013)

(a) Schematic illustration of formaldehyde sensor based on photometer and reagent-filled filter. (b) Variation of sensor response with formaldehyde concentration given sampling times of 1, 3 and 5 min [5].
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3673094&req=5

f5-sensors-13-04468: (a) Schematic illustration of formaldehyde sensor based on photometer and reagent-filled filter. (b) Variation of sensor response with formaldehyde concentration given sampling times of 1, 3 and 5 min [5].
Mentions: The instrument (Figure 4(b)) detected the surface color change of the detection tablet from white to yellow, which was monitored as a function of the intensity of the reflected light illuminated by an LED (475 nm). The response was proportional to the formaldehyde concentration. Kawamura et al. [5] proposed a hand-held formaldehyde gas sensor comprising an LED light source (wavelength 540 nm) and a circular filter impregnated with potassium hydroxide solution and 100 μL of 4-amino hydrazine-5-mercapto-1,2,4-triazole (AHMT, see Figure 5(a)). When the filter was exposed to formaldehyde gas, the AHMT reagent reacted with the HCHO and resulted in a change in the color of the filter. The color change was then recorded by measuring the intensity of the light reflected from the surface of the filter using a photodiode. The results showed that a minimum detection limit of 0.04 ppm HCHO was possible given a sampling time of 3 min or more (see Figure 5(b)).

Bottom Line: Accordingly, the emergence of sophisticated technologies in recent years has prompted the development of many microscale gaseous formaldehyde detection systems.Besides their compact size, such devices have many other advantages over their macroscale counterparts, including a real-time response, a more straightforward operation, lower power consumption, and the potential for low-cost batch production.This paper commences by providing a high level overview of the formaldehyde gas sensing field and then describes some of the more significant real-time sensors presented in the literature over the past 10 years or so.

View Article: PubMed Central - PubMed

Affiliation: Department of Architecture, National Cheng Kung University, Tainan 701, Taiwan. benjamin@archilife.ncku.edu.tw

ABSTRACT
Many methods based on spectrophotometric, fluorometric, piezoresistive, amperometric or conductive measurements have been proposed for detecting the concentration of formaldehyde in air. However, conventional formaldehyde measurement systems are bulky and expensive and require the services of highly-trained operators. Accordingly, the emergence of sophisticated technologies in recent years has prompted the development of many microscale gaseous formaldehyde detection systems. Besides their compact size, such devices have many other advantages over their macroscale counterparts, including a real-time response, a more straightforward operation, lower power consumption, and the potential for low-cost batch production. This paper commences by providing a high level overview of the formaldehyde gas sensing field and then describes some of the more significant real-time sensors presented in the literature over the past 10 years or so.

No MeSH data available.