Pyranometer optical domes
Pyranometers, used for measuring solar irradiance, are used outside of the safe laboratory environment and therefore require a rugged, protective cover window to protect the delicate detector within. Modern designs are manufactured as desiccated, sealed units to remove unwanted moisture from inside the system. It may not be as glamorous as the sensitive electronics within, but a well-designed and fitted protective window is essential in the pyranometers operation.
Knight Optical produce custom pyranometer domes and windows specially designed to meet these criteria. Manufactured from either N-BK7 glass or a suitable alternative, including sapphire, our products achieve tight tolerances and are fully tested in our extensive metrology laboratory. With customers in the solar industry worldwide, we consider ourselves to be the best solution for your pyranometer requirements. Contact our experts to find out why.
Our aim is to understand our customer needs working with ISO10110, BS4301-1991, and MIL-PRF-13830B, Knight Optical deliver optical components and sub-assemblies at the correct quality on time and within budget.
Whatever your project we will be happy to be involved; call our technical advisors for advice or submit your drawings here for a full quote within 48 hours.
Dome windows are hemispheres. The two optical surfaces are an equal thickness apart, creating a naturally strong shape that gets tougher under pressure. This makes dome windows ideal for high-pressure environments and applications that require a wide field of view such as pyranometers.
Our custom capabilities make our domes ideal for pyranometer applications. We offer tightly controlled form error for a consistent signal through the protective glass dome. Our domes can be supplied with or without flanges based on your design requirements and we are also able to supply our domes AR coated for wavelengths outside of the desired range to eliminate unwanted light. Coupled with our state of the art metrology testing and experienced sales force, Knight Optical can be your reliable partner for pyranometer optics.
Typically the material used will depend on the working wavelength of the application with Schott N-BK7 or equivalent, Fused Silica (Spectrosil), Sapphire and PMMA acrylic most commonly used. N-BK7 or equivalent offers a tough, cost-effective solution for visible range applications while Fused Silica is ideal for wavelengths below 400nm. Sapphire is used for its rugged properties and is suitable for harsh environments where a softer material would risk damage. PMMA is lightweight and cheap to produce in bulk. Modern plastics are increasingly tough and in many cases offer near identical optical properties to the glass while saving considerably in weight. For infrared applications, we can provide sapphire domes.
Knight Optical offer several stock domes between 25mm to 100mm diameter, made from quality glass at affordable prices. These sizes have been specially chosen to suit our customers' applications and are among our most popular products.
We also offer custom domes as part of our extensive optical design and manufacturing service. Custom parts can be manufactured from your own drawings or designed in-house by our experts. The table below shows just some of our custom dome capabilities.
Find out more about our Stock Domes here
|Diameter (mm)||5mm to 300mm+|
|Thickness (mm)||Dependant on diameter. Please ask for more information|
|Dimensional tolerances (mm)||+/-0.05|
|Max. strength variation* (diopters)||+/-0.2|
|Surface figure (fringes)||< 10(5)|
|Concentricity (mm)||< 0.05|
|Material||N-BK7 or equivalent, Fused Silica, PMMA, Sapphire and more|
|Mounting options||Unmounted or custom mounted|
|Coating options||AR coated for select wavelengths, ITO coated, Hydrophobic coated|
|Pressure tolerance||Dependent on size and material. Contact us for more information.|
* Strength variation relative to strength at peak of dome
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