SBIR-STTR Award

The High Precision Cavity Radiometer is an all digital dual cavity radiometer with a 600-fold increase in sensitivity over current cavity radiometers. This new detector is being proposed for use in two applications: (1) as a spaceborne sensor and (2) as a commercial laboratory instrument. First, the TUVIR (Total and Ultra-Violet Irradiance Radiometer) is a completely new spaceborne instrument which utilizes the new radiometer to measure the total solar radiation and the ultraviolet solar radiation in narrow, ozone related bands. The 200 to 250 nm ultraviolet component of the sun's radiation provides the energy for the formation of ozone in the Earth's atmosphere. This narrow spectral band only contains 0.14% of the total solar energy. To accurately monitor long term changes in this radiation a 600 fold improvement in sensitivity is required over current cavity radiometers. TUVIR provides this sensitivity. Second, commercial laboratory radiometers with greatly improved sensitivity are also required to accurately measure the output power of low level continuous wave lasers and to act as transfer standards from cryogenic calibration standards that operate in vacuum chambers. This High Precision Cavity Radiometer has the long term precision and absolute accuracy to provide a transportable reference standard with a durable shelf life.

The High Precision Cavity Radiometer is an all digital, dual cavity radiometer with a 3000 fold improvement in sensitivity over current cavity radiometers. A new solar monitoring instrument called TUVIR and also a commercial instrument will both utilize this new radiometer. The TUVIR (Total and Ultra-Violet Irradiance Radiometer) will use these new radiometers to measure the 220 to 250nm solar ultraviolet radiation as wellas the total solar output. The 220 to 250nm solar radiation provides the energy for the formation of ozone in the Earth's atmosphere. This narrow spectral band contains only 0.14% of the total solar energy and thus provides the driving requirement for the improvement in radiometer sensitivity. The TUVIR instrument contains 2 primary and 2 backup radiometers and a self calibrating shutter with contamination seal yet weighs less than 12 pounds. A commercial instrument using a single High Precision Cavity Radiometer will be used to accurately measure the output power of low level continuous wave lasers and to act as a transfer standard from cryogenic calibration standards that operate in vacuum chambers. The digital controller allows remote operation in vacuum chambers and provides improved long term stability.

Keywords:
RADIOMETER CAVITY ULTRAVIOLET SUN PRECISION TRANSFER LASER DIGITAL