Resumen de Using a Flatbed Scanner To Measure Detergency: A Cost-Effective Undergraduate Laboratory
J. A. Poce Fatou, Manuel Bethencourt Núñez, F. J. Moreno Dorado, J. M. Palacios Santander
The efficiency of a laundry-washing process is typically assessed using reflection measurements. A spectrometer and an integrating sphere are used to obtain the reflection data. The similarities between this equipment and a commercially available flatbed scanner are examined, and the way a flatbed scanner can be used to obtain detergent efficiencies is described. A flatbed scanner can be viewed as a singular spectrometer capable of obtaining spectral information concentrated in three regions of the visible spectrum. These data are stored in image files as coordinates in the red–green–blue (RGB) space where colors are represented by mixture of red, green, and blue in an 8-bit scale, that is, in a range where the intensities of these colors vary from 0 to 255. Detergent efficiencies calculated with these devices are compared. Washing tests on linseed-oil-impregnated white polyester fabrics are performed using sodium dodecyl sulfate with mass concentrations ranging from 0.00 to 1.00%. The results demonstrate that a flatbed scanner is a valuable and economical alternative to calculate detergent efficiencies in a wide variety of circumstances.
