Equipment for Temperature Measurement of Material Samples in a Vacuum Chamber
|514 - Abstract:|
The offered technology concerns equipment for non-contact temperature measurement of samples arranged in a vacuum chamber. It has particular application, although non-exhaustive, for testing materials destined for space missions; more particularly to space missions inside the Solar System or similar. The materials are then exposed to temperatures significantly higher than those recorded for Earth-orbiting space missions. As examples, the BepiColombo and Venus Express missions can be quoted.
The European Space Agency (ESA) is interested in finding companies interested in a license agreement.
Description of the offer:
To predict the behaviour of materials used, in particular their stability over time when they are subjected to high temperatures, conventionally initial tests are conducted in laboratory conditions wherein they are subjected to a thermal cycle, according to predefined profiles of temperature variation, in a predetermined environment simulating to the best the harsh environmental conditions encountered during the space missions: exposure to UV, VUV, EUV radiation, to X rays or even to elementary particles: electrons or protons, and to do so under high vacuum. To achieve this objective, samples of materials are arranged generally on supports, for example on plates in a chamber having a high vacuum and are subjected to programmed heating cycles. When tests are conducted on sample materials, the precise measurement of their temperatures which can be taken at different points of their surface, is therefore of fundamental importance.
The objective set by the invention is a non-contact temperature measurement equipment for a plurality of samples of materials arranged in a chamber having a high vacuum and exposed to an energy source that raises the temperature, said materials exhibiting thermo-optical properties, in particular different thermal emissivity coefficients.
To do so, according to a first feature of the offered technology, the temperature measurement system comprises a pyrometer associated to a two-dimensional scanning device. In a preferred embodiment of the offered technology, the scanning device includes a mirror, with high reflective power for infrared wavelengths, and a component that rotates the mirror according to two orthogonal axes. The mirror is positioned on the optical path between the pyrometer and the samples, ideally such that the pyrometer's focal point is located on the surface of samples.
This arrangement enables a focusing on the surface of a determined material sample, on a zone of small surface. This arrangement further enables the sequential scanning, not only of a plurality of samples of materials, advantageously of materials exhibiting different emissive coefficients. It also enables the creation of a detailed chart and specifies the full surface of each of the samples of material to be tested. Lastly, it should be noted that a two-dimensional surface map of temperatures does apply for samples surface, but also apply for the surfaces of a spaceship or of various components, for example, during a thermal balance test.
In a still further preferred embodiment, the scanning device further comprises a component enabling a translation movement following the three axes of an orthonormal trihedral, one comprised in a plane that shall be referred to arbitrarily as horizontal, the other in a vertical plane, thereby increasing its degree of freedom. In a still further preferred embodiment, when the samples of materials to be tested are made of film of slight thickness, the side of the support in contact with these samples presents a convex curve surface, such that the films can be pressed firmly against the support. It follows that a thermal contact of very high quality can be obtained. With this advantageous arrangement, the risk of samples detaching, as noted with plane supports, is thereby avoided.
Innovations and advantages of the offer:
- it enables non-contact measurement of samples of two-dimensional materials;
- it enables the measurement of a zone of very large size inside the vacuum chamber;
- it enables the raised measurement of thick samples or of a spaceship and components configured in three dimensions;
- it enables measurements without handling the radiation source, for example with UV, thereby allowing measurements in a total state of balance;
- it enables multiple measurements on each sample of the temperature of samples, while multiple measurements on the samples determine the uniformity of the sample's surface temperature;
- it enables frequent measurements, while frequent measurements on each sample determine and ensure the stability of temperature according to time;
- it enables measurements on different materials with different thermal emissivity coefficients.
- it authorizes the exposure of samples to a constant temperature throughout the process enabling, for example, the compensation of the radiation source's operational degradations (energy fluctuations), by means of a feedback loop acting on this source;
- due to the small dimensions authorized for the scanning device, the radiation source can be arranged very close to the samples of materials and thereby obtain an acceleration of the heating process.
Domain of Application:
- Analytical and Scientific Instrumentation
- Industrial Equipment and Machinery
Last update: 15 January 2013