método para aumentar o número de filtros óticos em um espectrômetro de furo descendente, e, ferramenta espectrômetro de furo descendente

摘要

Downhole spectrometer tools are provided with two ways to increase the number of filters on an optical path. A first approach employs multiple filter wheels that rotate alternately in a common plane to intersect the optical path. Portions of the wheels are cut out to avoid mechanical interference between the wheels. A second approach drives the one or more filter wheels with a wobble that causes the filters to trace one or more hypocycloidal curves that each intersect the optical path.