EnvirOptics hermetically sealed probes are designed and tested to perform under the harshest conditions including high and cryogenic temperatures as well as corrosive and abrasive atmospheres. High purity synthetic sapphire is the window material of choice for these probes because of its unique capabilities. Synthetic sapphire is capable of 80% to 90% optical transmission from UV through visible to infrared frequencies. Because of its superior mechanical strength to that of fused silica and glass, a much thinner window can be produced that is mechanically durable in harsh environments. Sapphire has a coefficient of thermal expansion that allows it to be brazed to a variety of high performance and corrosion resistant metals. Sapphire is more chemically inert than glass or quartz and is not affected by acids, strong alkalis or organic solvents.