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The company for the supply and support of state of the art instrumentation for use within Ballistics R&D and proof testing.

Internal Ballistics

Products designed for the study and analysis of the processes originally accelerating a projectile.

External Ballistics

Products designed for the study and analysis of the flight of a projectile through the air.

Terminal Ballistics

Products designed for the study and analysis of the interaction between a projectile or explosion and its intended target.


B471 Precision Light Screen HPI

Determining projectile velocity (v) by measuring the time (t) required to travel a known distance between two sensors has been a tried and tested method for some time. Chronographs with resolutions of .05 micro seconds are now available. The accuracy with which the projectile velocity can be recorded therefore depends primarily on the sensor. An exact trigger event is essential, irrespective of the projectile type, shape or velocity.

Any external influences, such as shock waves, which may effect the triggering point and therefore cause measurement errors must be eliminated. Therefore accuracy and reliability were the most important factors during the design of the HPI B471.

Technical Data

  • Calibre range 4 - 40 mm
  • Velocity range 50 - 2000 m/s
  • Safe passage area 820 x 1000 mm
  • Effective sensor area 600 x 1000 mm
  • Measuring base 2 m < ±1 mm
  • Thermal expansion 23.4 x1 0-6 1/K (0.468 mm pro 10 K)
  • Temperature range 0 - 40°C (32 - 104°F) ambient temperature
  • Trigger modes NOSE/BASE triggering
  • Counter frequency 20 Mhz (50 ns)
  • Duration of shading > 12 μs
  • Accuracy < ±0.1% for base trigger
  • When using NOSE trigger, accuracy depends on projectile shape, but is < ±0.5%

Rate of fire theoretically up to 20,000 rounds per minute, the actual rate depends on:

  • distance from the muzzle
  • shock wave
  • intensity of gas cloud (dust and smoke)
  • range design

Influence of tracer suitability mainly depends on the type of ammunition used.
Very bright tracers or clouding from dust and smoke can cause error signals
Power supply 85 - 265 VAC, 50/60 Hz
Consumption 0.5 A at 230 V
Rating approx. 40 W

Further advantages of the B471 Precision Light Screen

  • large sensor area
  • infrared transmitter and receiver
  • no controls on the light screen
  • unaffected by changing ambient light
  • simple connection to PC (or notebook)
  • interference immunity because signals are processed at the light screen and recorded times transmitted via the RS485 interface

Suitable for:

  • measurements in subsonic and supersonic ranges
  • tracer ammunition under certain conditions
  • individual shots and fire bursts
  • measuring shotgun ammunition (with reduced measuring base)

Photo: B471.

Image: B471
Horizontal View.

Image: B471 Vertical View.