Primary Standards For Traceable Infrared Temperature Calibrations

Freezing PointSanta Barbara CA, USA –?? The Electro Optical Industries (EOI) series of primary standard blackbodies are pure elemental freezing point blackbody radiation sources for use as primary standards of spectral radiance. The ITS90 temperature scale is defined by the freezing points of pure elements.

EOI freeze point blackbodies provide known spectral radiance at the ITS90 defined temperatures for gallium, indium, tin, zinc, aluminum, silver, gold and copper.

Special Features:

  • Interchangeable Freeze Point Crucibles
  • Reverse Cone Cavity Provides Highest Emissivity
  • One System for Multiple Freeze Point Temperatures
  • 2 Year Warranty


Each freeze point blackbody has a 0.25″ diameter reverse cone cavity.

The reverse cone configuration provides a highest effective emissivity, especially when compared to the more common straight cavity freezing.

The cavity configuration and graphite material yield a 0.9997 ??0.0003 effective emissivity.


The uncertainty of the spectral radiance is a function of the emissivity of the conical cavity (geometry plus surface characteristics), wavelength, thermal gradient across the cavity wall, purity of the melt material, uniformity and stability.

The calculated uncertainty of the spectral radiance of the EOI freeze point blackbodies is less than 0.1??C (< 0.01??C for Gallium).

Electro Optical Industries is a leader in advanced infrared and visible light spectrum test and calibration equipment.?? EOI provides:

Electro-Optical Industries, Inc.
859 Ward Drive
Santa Barbara, CA 93111-2960 USA

Phone +1 805-964-6701
Fax +1 805-967-8590