Bodycote Metallurgical Coatings :: Infra-red Windows

HOT ISOSTATIC PRESSING (HIP) OFFERS THE POSSIBILITY OF NORMALISING THE PROPERTIES OF INFRA-RED WINDOW MATERIAL TO IMPROVE TRANSPARENCY AS WELL AS REMOVING POROSITY OR BUBBLES.

HIP thus improves material properties and may also improve the microstructural homogeneity.

The Bodycote HIP division offers a sub-contract HIP service as an integral part of the production route for such high quality parts.

Principle

Zinc sulphide may be prepared by a reaction of alkaline sulphide with zinc saline solution.

The white precipitation of zinc sulphide is formed into preforms from which the infra-red windows are manufactured.

During the HIP process the zinc hydrides are removed from the zinc sulphide windows to make them perfectly transparent.

Infra-red windows from other materials including magnesium flouride and calcium aluminate are also regularly HIPped to remove porosity and improve both transparency and mechanical strength.

Data from Remote Sensing

Earth resource information satellites have been operated by space agencies since the beginning of the 70's.

The US Landsat-5 remote-sensing satellite orbits the earth in an almost-true polar orbit at an altitude of 705 km.

Landsat 5 carries a multi-spectral scanning system called the "Thematic Mapper" (TM).

The satellite images a 185 km-wide strip along the earth during each orbital cycle of 1-1/2 hours.

The entire surface of the earth is thus surveyed in 16 days. Data is digitalized and radio-transmitted to ground stations, which record it on magnetic tape.

The satellite's thermal resolution quality is about 1,500 points, or pixels, per line. Each point equals a surface area of 120 m x 120 m.

Flight patterns during the day and night are not identical, resulting in different image sectors in the resulting maps. Night scans of this area must be specially ordered by way of the ground station of the European Space Agency (ESA) in Italy.

The seven total spectral ranges of the Landsat-TM are in wave-lengths from the 0.45 µm of blue-green light, to the 12.5 µm of heat-infrared.

The longwave spectrum between 10.4 and 12.5 µm was selected for the imaging of surface temperatures.

This portion of longwave radiation emanating from the earth itself can pass relatively undisturbed through the atmospheric layers. It is called the "infrared window“.

Information

http://www.icf.de/UISonline/dua96/html/d406_02.htm

Applications:

Plastics industry

Food industry

Glass industry

Forging industry

Tool making industry

Mineral and mining industry

Wear and corrosion protection