Currently systems with similar performance characteristics, equipped with multispectral optical heat-seeking heads are operational only in the United States and France.
目前系统相似的性能特点，配备了多光谱光热寻的头是可操作的只有美国和法国。
2
The opposite side of the moving surface is provided with a single absolute type optical rule and two groups of read heads.
以及在该运动台面的相对侧设有单支的绝对式光学尺及两组读头。
3
2 projecting heads for table cinematographs, 1 optical sound head, 1 carbon arc projection lamp, 1 slide projector and more. All untested.