Flame detector is a type of sensor that can detect and respond to the presence of a flame. These Detectors have the ability to identify smokeless liquid and smoke that can create open fire. It’s easy to find flame detectors are exist in industrial warehouses, chemical production plants/stores, petrol storage and pump stations, power plants, transformer stations and many other place need to avoid open fire.
In all the components of flame detector, the window is the main component that exists as a protection for the sensor but does not affect the normal operation of the sensor, generally using BK7, Sapphire, Float glass, Quartz and other materials. However, because flame detector generally works in a special working environment, may face corrosive gases, high temperature, high heat, friction and other harsh working conditions, so sapphire may be the most ideal window material in terms of characteristics.
Here are basic properties of sapphire materials, you can easily find out why it is the ideal materials for covers.
.Transmission percentage of different light frequency. (Uncoated)
Visible Light: >85%
Infrared: 85% (0.75~4μm);70%(4.7μm);50%(5.2μm)
Ultraviolet: 80% (0.4~0.3μm); 60%(0.28μm);50%(0.2μm)
.Hardness: Mohs 9 , Knoop≥1700kg/mm²
Due to the excellent mechanical strength and friction resistance, the window can be thinned without meeting the same properties as other types of glass
.Thermal Expansion: 6.7 x 10-6 // C-axis.
.No attacked by acid or alkalis ,only attacked by HF at 300℃.
If you have any further questions about sapphire material and custom sapphire windows, welcome to contact us.
You can also download the properties of sapphire by click the following links. Sapphire Properties.