Lummer-Brodhum phtometer
陆末-布洛洪光度计

• unlimited exposure
• unmagnetized
• unmoderated
• unmodulated
• unoccupied level
• unpacking
• unperturbed
• unplugged
• unpolarized
• unpolarized light
• unpredictability
• unquantized
• unreflected
• unrelated colo[u]r
• unreliability
• unresolved lines
• unresonant system
• unsaturation
• unsealed system
• unshaded area
• unsharp
• unsharp image
• unsharp line
• unshielded
• un shielded telescope