Due to the extreme dependence of our thermal emission behavior on the wavelength of the thermal radiation due to the extreme dependence of our thermal emission behavior on the wavelength, only certain wavelengths are effective for thermal measurements. The following graphs show the range of thermal transmission of the most common thermal lenses as well as window materials for infrared thermometers. The blue-colored curve demonstrates the general rule applicable to all materials and represents the average value over an interval of temperature from zero (black) to infinity (green) that is the cold-pressure limitation (CPL).
For windows and lenses the cold-pressure limit is defined as the maximum measured value of the damping ratio of a material against the thermal gradient. This ratio is calculated as a function the temperature variation along the viewing angle for given viewing angle and the cte of a lens or window. The bending moment of an object is the change in the angle of incidence, which is linear or spherical. This makes the slope proportional to this curve. The slope of this curve is also proportional to the focal length of the system, which is considered as a function of the focal length divided by the duration of the curve (i.e. the interval between shots).
For a particular set of temperatures and a specific focal length of a lens or window assembly, the inside temperature of the system will always fall within the prescribed range in the perfect order called a “curved surface.” For instance the curve of thermal conductance of a glass piece inside a glass vial having an opening in it can be plotted as a function of the focal length and the temperature difference within the vial between the bottom of the bead and the vial’s surface, and the angle of incidence for a specific window assembly. If the aperture is fixed for all shots then the area between the system’s surface temperature and the curve of variation should remain constant. If the aperture is variable, then the curve may be curved because of the variations in the temperature of the glass used to create the bead and the temperature of the ambient air that is circulating on the inner surface of the vial, and the focal length and time of shooting. A typical example of a curly surface can be seen in the signature left by a photographer of a flower.
Mounting a lens and window should be done in a way that their focal points, and lines of sight, are correct. If the interior surface temperature of the system is too cold for the lens, the outside temperature of the frame and the interior temperature will be too high. When the outside temperature of the lens and the frame are the same, then the frame will not require any adjustments to compensate for the heating or cooling effects of internal temperature differences. If there aren’t any temperature variations from outside, then the system’s internal temperature will be the same for a given focal length. If the system is located in an area that has limited or obstructed views of the surrounding structures or landscape it might be necessary to regulate internal temperatures.
The first mechanical interlocking mechanism used to attach lenses to cameras were made of plastic. This design was later adapted to pinhole glasses. The issue with this kind of lens assembly is that the mechanical joints between the lens and frame may indent or break. If this should be happening, it will be essential for the entire system to be replaced within an extremely short amount of time. This is the reason why this system has been replaced with more durable designs.
Lenses made for use with pinhole glasses typically have frames made of metallic and a thin plastic or glass lid. At the very least the lense designs should include a hermetically sealed lens construction. A lens that is hermetically sealed has a sealed surface at the bottom and top. The top surface may contain an elastomeric seal similar to the one described above. Additionally, it could contain some other substance, for instance, an adhesive, a lip or a layer of plastic film.
A lens surface that contains a substrate and adheres to the base is an additional embodiment of this type lens and window assembly. This system usually consists of glass casings and series lens compartments. The windows can also house different kinds of devices such as light emitters or thermometers. This type of system could also include a thermostat or light emitter that controls the temperature of the room. A number of compartments could be used to house the temperature control and a variety of other devices like an alarm clock, thermostat, or other devices.
This is not an exhaustive list of all the types of lens and window assemblies. However, it is indicative of the most important technologies that are related to this invention. For more details, please look over the entire disclosure. Refer to the sections that pertain to “details about the present invention” and “Description Of the Process With Respect To the Identification of the Different Classes of Products which are involved in the Present Application.”
know more about lens and window here.