Dome lenses 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 underwater environments and in applications such as camera dome ports and submersible windows.
Sapphire domes: For infrared applications we can provide sapphire domes. Sapphire is an extremely hard material with transmission of over 80% in the 2-5µm wavelength range. As with fused silica, sapphire is able to withstand extreme pressures, making it the perfect material for underwater camera and missile fairing applications.
Specifiation of our dome lens as follow: Hk9 Glass Dome Lens,Hk9 Hemisphere Domes Lens,Hemispheric Glass Dome Lens,Optical K9 Glass Dome Lens China Star Optics Technology Co.,Ltd. , https://www.csoptlens.com
BK7 or K9L domes are used primarily in meteorology applications. BK7 offers excellent transmission from 300nm up to 2µm. BK7 is a relatively hard material, with excellent chemical durability.
UV fused silica domes ( JGS1 ): For applications operating in the deeper UV range, we offers a range of UV fused silica domes. Fused silica domes are commonly used in underwater applications at extremely high pressures.
Material:Optical glass N-BK7 , H-K9L, UV Fused Silica, Sapphire, and infrared crystal materials.
Diameter:20-350mm
Diameter Tolerance:+/-0.1mm
Thickness:>2mm
Thickness Tolerance±0.2~0.1mm
Center Deviation:3-5'
Surface quality:80/50 60/40
Coating: Antireflection Coating inside or both sides
Chamfers:0.2 x 45° typical
Buy two mistakes in children's furniture
Parents often want to create a safe and healthy environment for their children, but when it comes to choosing children’s furniture, many are confused about what is truly safe and environmentally friendly. The market is flooded with various options, and conflicting claims from salespeople can make the decision even more challenging. Some say bright colors stimulate a child’s development, while others warn that lighter tones may be safer. These contradictory messages leave parents unsure of where to turn.
The color of furniture does not necessarily indicate its safety. Many manufacturers use vibrant paints to attract buyers, but this doesn’t mean they’re free of harmful substances like heavy metals. In fact, some brightly colored furniture may contain higher levels of lead or cadmium. A salesperson at one store claimed their products were softer in color and therefore more eco-friendly, which led a customer to sign a contract worth over 8,000 yuan for a bed, desk, and chair. However, when questioned about the safety of bright-colored furniture, another salesperson insisted that their products met environmental standards and even provided a test report—but only for formaldehyde levels, not for heavy metals.
Experts disagree with the idea that brighter colors mean more toxins. According to the Secretary General of the China Furniture Association, the color of the paint has no direct relationship with harmful substances. Whether a color is light or dark, if the paint contains heavy metals, it can still be unsafe. Therefore, consumers should always ask for detailed test reports from manufacturers before making a purchase.
Another common misconception is that solid wood furniture is automatically safe. While many parents believe that natural wood is healthier, the reality is more complex. Even solid wood furniture may use adhesives and paints that release formaldehyde or contain heavy metals. For example, solid wood veneer furniture uses more glue, increasing the risk of harmful emissions. Additionally, the paint on the surface can also be a source of contamination. Wood-based panel furniture, such as particleboard or MDF, is often coated with paper or synthetic materials, which may not contain heavy metals but could still emit formaldehyde.
When purchasing children’s furniture, it’s important to check both the material and the paint. The environmental protection level of different boards varies, with solid wood being the most desirable, followed by plywood and laminated timber. Water-based paints are generally more eco-friendly than traditional oil-based ones, but even these should be verified through proper testing.
In short, parents should not rely solely on color or material type when selecting children’s furniture. Instead, they should look for comprehensive test reports, pay attention to both formaldehyde and heavy metal content, and choose products that meet strict environmental standards. Making an informed decision ensures a safer and healthier living space for their children.