Figure 17

Telemicroscope images of a channel wall edge of the SPT-100D at different object distances. As indicated by arrows, the focal point moves along the eroded slope. Images were taken after about 300 hours of operation
Telemicroscope images of a channel wall edge of the SPT-100D at different object distances. As indicated by arrows, the focal point moves along the eroded slope. Images were taken after about 300 hours of operation