Development of a low-cost portable colorimeter for the estimation of fluoride in drinking water

Simplified Low-Cost Colorimetry for Education and Public Engagement

“…When designing the colorimeter, various detectors were considered on the basis of their previously reported success for colorimetry applications, including silicon photodiodes, ,,,, light-emitting diodes (LEDs), ,, phototransistors, , and light-dependent resistors (LDR). ,− After considering numerous reviews and experimental comparisons of potential detectors, , a light-dependent resistor (LDR) was chosen to reduce the potential cognitive load for the intended audience of young novice science students and the general public. , Unlike the other detectors, which are more frequently used for homemade colorimetry, the resistance value (measured in Ω) obtained from an LDR is inversely proportional to light transmittance . Therefore, the numerical values obtained from the colorimeter correspond directly with the concentration of the analyte being measured (i.e., higher resistance values correspond to higher concentrations, and lower resistance values correspond to lower concentrations).…”

“…Many learners have difficulty with abstract concepts without context, so it is important to present science (particularly chemistry) in a context that is relevant to them . Context-driven courses for chemistry are reported to be more motivating and interesting as well as more likely to encourage students to study chemistry for longer. , Many experiments reported for teaching spectrophotometry are based on solving real-world problems by quantifying analytes such as proteins or investigating fresh-water samples. − Therefore, it would seem that spectrophotometers are well suited for context-based-learning (CBL) activities, particularly for younger audiences and members of the public who generally possess relatively low levels of practical chemistry expertise. However, the sealed “black box” nature of modern spectrophotometers mystifies the process taking place within the instrument, which can hinder the intended learning from an otherwise well-designed experiment.…”

Design And Implementation Of A Photocolorimeter Using Microcontrollers To Determine Analyzes In Aqueous Solutions

“…Utiliza LEDs como fuente de luz y un fotodiodo. Costo del sistema de aproximadamente 5 USD (necesita un voltímetro) [6], o el trabajo de Gerald C. Anzalone del instituto de la Universidad Tecnológica de Michigan, en el que se diseñó un fotocolorímetro con hardware y software Open-Source para medición de la demanda química de oxígeno COD [7]. Un ejemplo similar es el trabajo de Suchita P. Bhangale del Nowrosjee Wadia College, Pune, India.…”

The Evaluation of a Low-Cost Colorimeter for Glucose Detection in Salivary Samples

“…Colorimetric techniques have been extensively applied for chemical and biochemical detection of relevant analytes in food control, environmental, biomedical and educational fields [ 1 , 2 , 3 , 4 , 5 ]. Recently, custom colorimetric systems have been developed, motivated by the simplicity of colorimetric techniques to demonstrate spectroscopic principles, the cost reduction experienced on electronic parts and the development of low-cost manufacturing techniques such as 3D printers.…”

“…Recently, custom colorimetric systems have been developed, motivated by the simplicity of colorimetric techniques to demonstrate spectroscopic principles, the cost reduction experienced on electronic parts and the development of low-cost manufacturing techniques such as 3D printers. These systems exhibit characteristics such as portability, low power consumption, ease of use and data transmission potential, and they can be assembled with inexpensive materials [ 1 , 6 , 7 , 8 , 9 , 10 , 11 , 12 ]. The excitation of samples in custom colorimetric systems is usually carried out with light emission diodes (LED), which present advantages over conventional light sources such as low power consumption, long lifetime operation, ease of instrumentation and a variety of defined wavelengths in the visible spectrum, which avoid the use of monochromators [ 13 , 14 , 15 ].…”