Ou GUIDED WAVE probes and flow cells offer high throughput, collimated optical beams through the sample, yielding lower noise and more accurate transmission values free of sample index of refraction effects. For faster maintenance and cleaning of insertion probes, the Extractor Mechanismv can be used. The controlled extraction of an in-line probe from pressurized process streams or reactors can be accomplished without shutting down the process, allowing continued use of the analyzer to verify process quality. Coupled with a gate or ball valve, these extractors have proven safe and effective in a variety of refinery installations such as Reformer, Gasoline Blending, Blender and Feed Streams saving downtime.