cyclograph
(1)圆狐规
(2)特种电影摄影机，轮转全景摄影机

• sighting gear
• sighting mark error
• sighting piece
• sighting telescope
• sighting wire
• sight level
• sight vane alidade
• sigmoidoscope
• sign
• signal
• signal averager
• signal beam
• signal-carrying laser beam
• signal conversion
• signal distortion noise
• signal entropy
• signal flow
• signal-generating image tube
• signal generator
• signaling
• signal-integrating
• signal intensity
• signal lamp
• signal level
• signal light