Ballistic measurement systems: measuring projectile’s end velocity (1972)

Measuring projectile’s end velocity (1972)

This measuring device determines projectile speeds at the location of an imaginary target at a large distance from the cannon (1 to 2 km). The spread of the projectiles at this distance is large. The system is therefore designed with a large detection field: a diameter of 8 metres and a flight height of a 105 mm projectile of 10 metres. This measuring device was built in collaboration with TNO-TPD. The system was handed over to the Commission of Trials of the Royal Netherlands Army in 1972.

The measuring device consists of two optical units. Each unit contains three optical detectors with contiguous fan-shaped detection fields, and an amplifier unit. The three optical detectors per unit are necessary to obtain a detection plane with an approximate 90° opening angle. The two optical units are provided with directional means to arrange the two detection planes in parallel. The units are placed at a distance of for instance 20 metres of each other. The flight time of the projectile is measured with two time-interval meters (counters t1 and t2) (see diagram).

Ballistic measuring projectile's end velocity (1972)
Ballistic measuring projectile’s end velocity (1972)

The printout converter or PRICO supplies the measurement data to a telex. The projectile velocity can be determined from the measurement data.

Schematic design of the end velocity measurements
Schematic design of the end velocity measurements

 

In July 1979, one of the end velocity detectors was hit in Petten by a 25 mm projectile
In July 1979,  25 mm projectile hit one of the end velocity detectors and destroyed it

 

Control Unit
Control Unit

 

The interior of the vehicle with the optical measuring systems, e.g. the amplifier unit of the end velocity meter. At the right the print-out converter rack (PRICO4) with the counters or the time interval meters
The interior of the vehicle for the optical measuring systems, e.g. the amplifier unit of the end velocity meter. At the right the print-out converter rack (PRICO4) with the counters or the time interval meters