About Light Boxes

Thank you for visiting this web site. The goal of the site is to describe simple procedures for measuring the amount of various chemicals in solutions using light absorption, light scattering and fluorescence.

The circuit board is designed to hold a microprocessor for communication with a PC. I also enjoy building basic circuits with an LED and a light detector and using a multimeter to read the output. The detectors are light-to-voltage converters, light-to-frequency converters, or, in the ultimate example of simplicity, a photoresistor.

I built the light boxes described in this site in my garage. The housings are one-off plastic prototypes that hold the cuvette, the circuit, and one or two optional light filters. At some point in the future I may manufacture more of the housings and at that time I would be happy to provide the light boxes as kits to anyone interested in them.

Again, thanks for visiting,

David

Terms and definitions

Light box - A simple photometer.

Light filter - Thin colored plastic strip. Used to modulated the color or intensity of light. Each filter has well known spectral characteristics. The filter can be used to alter the light from the source before it passes through the sample (for example, to change its color), or before and after the light passes through the sample (for example , for detecting optical rotation using plane polarized filters).

Microprocessor - Used to send the output of the light detector to a PC for visualization and analysis.

Multimeter - Electronic instrument to measure voltage, resistance, frequency and multiple other signals. Available at any hardware store or electronics shop.