photographic densitometer
光密度计

• screen persistence
• screw
• screw axis
• screw cap
• screw drive
• screw-driver
• screw ga(u)ge
• screw gear
• screw-in filter cell
• screw micrometer
• screw-on surface
• screw pitch
• screw plug ga(u)ge
• screw ring ga(u)ge
• screw testing interferometer
• screw thread
• screw thread gage
• screw thread micrometer
• screw-type lens mount
• scroll
• scuff-resistant coating
• Seal
• sealed nitrogen laser
• sealed-off counter
• sealing