USB Spectrophotometer

What is a spectrophotometer you may ask? Basically it's a device that uses different wavelengths of visible light (and sometimes even infrared or ultraviolet) to collect data. The light is passed through the substance, which is usually in liquid form or is in solution, and the intensity of the light reaching through the sample is measured. Different substances of different concentration will interact with the light differently, so that the composition or concentration of the substance can be calculated.

Step 1 Materials

Materials needed:

LEDs of different colours - as many as you want

Resistors to match the LEDs - depends on amount of LEDs

Photoresistor - used to measure light intensity

USB cable - used to provide power to the circuit

Case - helps to keep out unwanted light and keeps things organized

Multimeter - to measure the resistance of the photoresistor, and to help build the circuit

Optional:

Switches

Connectors

Comments

[DIY-Guy]

Anybody got a way to cycle through all the colors using those RGB (color changing) LEDs to do this? It could create many different colors for this colorimeter.

[ancienthart]

This is a cool build, and one that I've thought of before, but technically this is a multi-channel colorimeter, not a spectrophotometer.