PTB’s Coldscreen: an intermediate manufacturing step
To operate, the spectrometer that will fly on the European Space Agency’s upcoming FORUM mission needs a reference source – a device that will be used to calibrate the instrument to make sure its measurements remain as accurate as possible while in space.
For a spectrometer of this kind, this reference source is a ‘blackbody’ – a physical object that, in theory, absorbs all electromagnetic radiation and reflects none. The National Institute of Germany (PTB) have developed a reference blackbody that allowed them to calibrate the blackbody which will actually fly on FORUM.
A blackbody can only serve as a reference source with the lowest uncertainty if its surrounding temperature is stable, known and uniform. For this, PTB have developed a coldscreen – a highly emissive black plate very uniform in its temperature. This image shows the tubing on the inside of the coldscreen, optimised for achieving a highly uniform temperature of the coldscreen’s surface.
[Image description: This is a photo of a vertically mounted metal plate with a precisely arranged pattern of copper tubing. The tubing follows a series of smooth, wavy, parallel lines across the surface. The plate is secured at the top by two black clamps. In the background, a laboratory environment is visible.]
