The ISO5 integrating sphere from Ancal Inc. was designed for use with miniature fiber optic spectrometers. It measures 0.94 in. in diameter, 1.0 in. in height and 1.5 in. in width with an SMA connector that allows it to replace radiometric and quantum sensors without changing reception characteristics. The sphere provides cosine reception of spectral radiation from ultraviolet C through the near-IR in most locations, and its quartz input window offers spectral transparency from <210 to >1100 nm. The inside surface is a highly reflecting white for sensitivity better than 95% above 300 nm. The device has a domed top to prevent excess water buildup.