| 摘要 |
<p>The double grid monochromator has an input slot, a first diffraction grid an intermediary slot, a second diffraction grid and an output slot. These elements are optically connected to each other and arranged in the direction of propagation of light. A scanning device modifies the angular positions of the diffraction grids in the course of exploration of the emission spectrum. The scanning device has a first electric motor kinematically connected to one of the diffraction grids and a second electric motor kinematically connected to the other diffraction grid. It also has two transmitters for the angular positions of the grids. A programmer generates signals determining the angular positions of the diffraction grids during exploration of the emission spectrum giving a relation between the angles of incidence of light on the two diffraction grids. Two comparators form signals corresponding to the difference between signals applied to their two inputs. One input of each comparator is connected to one of the outputs of the programmer and the second input to the output of the transmitter of the angular position of the corresponding diffraction grid. Two mixers each have an input connected to the output of one of the comparators and an output connected to the input of the corresponding electric motor.</p> |
