The NearSys LED Photometer Kits

Discovered by Forest Mims in the 1970s, LEDs behave as inexpensive, spectrally sensitive photometers. The NearSys Photometer kits permit near space missions to measure the brightness of sunlight as a function of altitude in a number of colors. Each photometer has two LEDs and a temperature sensor. Adding a polarizing film to the LEDs converts the unit into an affordable photopolarimeter.

The LED photometer kit includes two complete photometers with infrared, red, yellow, and green LEDs. The cost for the kit is $17.00 plus $4.00 S&H. To make the photometers more useful, they should be combined with the NearSys Sun Sensor.