Due to the extreme dependence of our thermal emission behaviour on the thermal wavelength, only certain wavelength ranges are suitable for measurements of thermal. The following graphs show the range of thermal transmission of common thermal lenses and window materials for infrared thermometers. The blue-colored curve represents the general rule for all materials. It is the average value across the temperature range of zero (black), infinity (green) and that is the cold-pressure limit, (CPL).
For lenses and windows The cold-pressure limit can be defined as the highest value of the damping ratio of a material against the thermal gradient. This ratio is calculated as a function the temperature variation along the angle of view for given viewing angles and cte of a lens or window. The bending moment of a system is the change in the angle of incidence, which is spherical or linear. This results in the slope being proportional to the curve. The slope of this curve is also proportional to the focal length of the system, which is thought of as an expression of the focal length divided by the duration of the curve (i.e., the time between shots).
For a set of temperatures and a given focal length of a lens or window assembly, the inside temperature of the system will always be within the prescribed curve in an exact regularity, also known as a “curved surface.” For instance, the curve for the thermal conductance of a glass piece inside a glass vial with an opening in it can be plotted in relation to the focal length and the temperature difference inside the vial between the bottom of the bead and the surface of the vial, and the angle of incidence for a given window assembly. If the aperture is fixed for all shots, then the area between the system’s surface temperature and the curve of variation must remain the same. If the aperture is adjustable this means that the curve could be curving as a result of the variations in the temperature of the glass used in the making of the bead, the temperature of the ambient atmospheric air on the inside surface of the vial and the focal length and time of shooting. A signature left by photographer on a flower is an example of a curving surface.
Mounting a lens and window must be done to ensure that their focal points, and lines of sight, are correct. If the temperature of the inside of the system is too hot for the lens, then the outside surface temperature of the frame will be lower and the inside temperature of the lens will be too hot. The frame won’t need to be adjusted in order to compensate for internal temperature fluctuations or cooling effects. If there are no temperature variations from outside, the frame’s inside temperature will be the same for a given focal length. However, if the camera is installed in a location with an obstruction or limited view of any nearby building or scenery the internal temperature may require adjusting.
The first mechanical interlocking system that was used to attach lenses to cameras were made out of plastic. This design was later adapted to pinhole glasses. This type of lens assembly is not without a problem: the mechanical joints between the lens and frame might crack or indent. If this should be happening, it would be required for the entire assembly to be replaced in the shortest amount of time. Because of this, this type of system has been replaced by more robust designs.
Pinhole glasses lenses are typically constructed using a frame of metal and a thin, glass or plastic lid. These lense designs should at the very minimum have a hermetically-sealed construction. A hermetically sealed lens construction has an enclosed surface at the bottom and the top. The top layer could be a part of a mechanical seal similar to that described above. Additionally, it could contain a different substance, such as an adhesive, a lip or a layer of plastic film.
A lens surface that contains an adhesive and is bonded to the base is a different embodiment of this type lens and window assembly. This type of system usually consists of a window casing and a series of compartments for lenses. The windows may also contain different kinds of devices like light emitters or thermometers. In some cases, the device used to control the temperature within the room could also be part of this type of system. In this case there are a number of compartments that could house the temperature control together with a variety of other devices, including an alarm thermostat or clock.
This isn’t an exhaustive list of all the types of lens assemblies and windows. It is however a good indication of the key technologies that are related to this invention. Please refer to the complete disclosure for more details. Particularly, you should look over the sections that pertain to “details of the Present Invention” and “Description of the Method with Respect to the Identification of the Different classes of products Included in the Present Applica.”
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