PAR detector
The CSS-45 PAR spectral detector packs the full capability of a spectroradiometer into a compact metal housing only 1.75 inches in diamete and 2 inches high. It covers a spectral range between 360 and 830 nm. It measures photosynthetic photo flux density in μmol/m²s, illuminance in lux from 1 to 350,000 lx, and color quantities. The detector head attaches to a computer via USB cable. All measurement, data readout and data logging is controlled by the supplied software.
from Gigahertz-Optik