Pin oscillographic technique

The determination of detonation velocity is based upon measurement of the time interval needed for the detonation wave to travel a known distance through the explosive under test. The methods used to determine VOD may be classified as mechanical methods (Dautriche method), electrical methods [pin oscillographic technique (POT)], optical methods and radiographic methods. The methods which are generally used for the determination of VOD are  

Probes The probes are of pin type with diameter less than 1 mm which can withstand high pressure and temperature. There are mainly four types of probes which 

Event Box It consists of R-C network and a minimum of six sections of such networks are taken in a single event box. The positive power supply is given for three sections of the R-C network whereas negative power supply is given to the 

The oscilloscopes also have a built-in cursor measurement facility which helps in measuring the period between pulses with accuracy better than 1%. The plotter can be attached to the oscilloscope to have a hard copy record. 

The time interval needed for the detonation wave to travel the pre-determined distance between two probes is measured using built-in cursors of the oscilloscope. The detonation velocity is then calculated as a quotient of the distance between two probes(d) and corresponding time interval (t). Similarly the VOD is 

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Detonation Transients and Unstable Detonation Processes. Allen et al (Ref 1) made detonation velocity vs chge length. measurements on RDX (—65+100 mesh), fine grained TNT (—35 —150) coarse, low-density TNT (—8+10) 50/50 fine-coarse TNT, cast TNT, low-density. mixts of 80/20 TNT/AN, and mixts of 90/10 AN/RDX. Deton velocities were measured by a rotating mirror streak camera and by the pin oscillograph technique, in most cases simultaneously Their exptl data showed six different types of velocity transients ... 

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