Optical fibres fast photodiode/oscilloscope

If the optical fibres/fast photodiode/oscilloscope technique is used, an oscillogram similar to the one in Figure 4.16 is obtained. By further treatment of the oscillogram, the detonation velocity is obtained as a ratio of distance traveled and corresponding time interval. 

Figure 4.30. Test airangematit for die determination of the detonation velocity using the optical fibres/fast photodiode/oscilloscope technique...

Another possible way of registering the arrival of the detonation wave on the optical fibres is to transform the light signal from the fibre by a fast photodiode that has a rising time of about 10 ns into an electric signal that may be recorded either by a fast oscilloscope or a multichannel analyser (Figure 4.30). 

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