Optical Process Probe integrates sapphire window.

Transmission probe SWOPP03C has polished sapphire lens sealed into 316 stainless steel body, offering chemically inert, abrasion-resistant interface to material under test. Along with 2,040°C melting point and 0.17-5.5 micron optical transmission range, sapphire is trigonal crystal of aluminum oxide that has Young's Modulus of 330 GPa and shear modulus of circa 150 GPa. Probe comes with 600 micron internal glass fiber and permits measurements at pressures to 10,000 psi and 400°C.