equality of brightness photometer
等亮度光度计

• paper polishing
• paper tape
• paper tissue
• parabocone
• parabolic
• parabolic antenna
• parabolic approximation
• parabolic equation
• parabolic index filbre
• parabolic mirror
• parabolic reflector
• parabolic-shaped collector
• paraboloid condenser
• paraboloid eyepiece
• paraboloid hyperholoid mirror
• paraboloid mirror
• paraconductivity
• paracrystalline array
• paraelectric phase transition
• paraffin
• parafocusing
• parafocusing arrangement
• parafocusing method
• parafocusing spectrometer
• parahboloidal mirror