The Cyclops Model 878 is a spherical blackbody source. It consists of an inner black sphere that sits inside a spherical furnace and is suitable for use as a radiation source for infrared thermometers.
The inner sphere has a nominal diameter 230mm and is accessed by an optical sightings tube. The furnace can be supplied in one of two constructions, one providing an aperture size of 17mm and one of 45mm.
The emissivity of the material is 0.98. The outer case viewing hole has an aperture of 17mm as standard. An aperture of 50mm is available to special order, giving an apparent emissivity in relation to the wall greater than 0.999.
The furnace can be adapted for thermocouple operation by replacing the inner sphere with an equalizing black and using a different control sensor.