billet split lens
比勒对切透镜
Billet split lens
(Billet half lens )比累分裂透镜(比累半透镜)

• root-mean-square displacement
• root-mean-square error
• root-mean-square value
• rope pulley
• rosette method
• rosette scan
• rosin
• Ross corrector
• Ross wide angle lens
• rosy
• rotameter
• rotary
• rotary diaphragm
• rotary indexing table
• rotary index table
• rotary microfilmer
• rotary mirror switch
• rotary plane workholder
• rotary platform
• rotary power
• rotary prism
• rotary-scanning spectroscope
• rotary table
• rotary wave
• rotating bexagonal prism