Radiometric Calibration Transfer

Integrating spheres show very uniform radiance distribution and are used in a range of applications for the testing and radiometric calibration of imaging and non-imaging systems such focal plane arrays and cameras. One typical application includes the test and calibration of satellite cameras and instruments for multi-spectral and hyperspectral imaging. Often calibration would require downtime and shipment back to the manufacturer’s lab. Since this is rarely practical, customers are looking for a way to calibrate at their location. To meet the needs of integrating sphere owners who have system lamps with high operating hours, light sources more than two years old, or a mandate for annual calibration, calibration on-site can be accomplished with the SR-4500 and SR-4500A portable spectroradiometers. With on-site recalibration and certification, there is minimal downtime. The SR-4500 spectroradiometer can be taken to any location. Weighing eleven pounds, it is easy to transport and use on-site, saving time and money and providing accurate and NIST traceable calibration transfer. With a 12″ x 4″ footprint it takes up very little valuable benchtop real estate. The SR-4500 provides an expanded spectral range of 350-2500nm. It includes three thermoelectrically cooled photodiode arrays to work efficiently in a wide range of ambient temperatures and environments (15-40 degrees C). Equipped with DARWin SP Data Acquisition software, it automatically saves scans in ASCII files for use (without pre-processing) by third party analytical software. Collect data with a single click and display reflectance/transmittance data (percentage) or absorbance (logarithmic) versus wavelength. Single and multiple spectral plots are available as well as LabVIEW drivers to create custom applications.

The SR-4500A has the same features plus enhanced drift stability of 0.1%. This offers the ability to more accurately calibrate integrating spheres and light sources that calibrate precision sensors in satellites, hyperspectral systems and UAVs. Better sensor calibration results in better quality and interpretability of remote sensing data.

The SR-4500 and SR-4500A are ideally suited for radiometric calibration transfer. They offer an expanded UV/VIS/NIR range, with the following features:

  • 350-2500nm – three TE-cooled photodiode arrays (1 Si/2 Extended InGaAs)
  • USB and wireless Bluetooth communications
  • 1.2 meter metal clad fiber optic cable with SMA-905 connector
  • Variety of fiber optic lenses including 1, 2, 4, 5, and 8 degree