Simple, cheap, and portable colorimeter for introductory analytical chemistry laboratories

چکیده مقاله

The construction and application of a cheap, simple and portable colorimeter is presented. The system employs an LED as a light source and a common photocell (photoresistor) as a detector. The device functions based on the level of light received by photocell, which is connected to a digit multimeter yielding resistance readings. Resistance increases with increasing the sample absorption. Due to the simplicity of the instrument it can be constructed in a laboratory or a classroom. The fabricated device is applicable to calculate the molar absorption of colored species and demonstrates the basics of the instrumentation of spectrophotometers.