Fire-TICs logo


P4444

Camera for mounting in a full face helmet / breathing apparatus unit. Developed in partnership with GB Solo and shown on BBC Tomorrows World in December 1990. Electrically similar to the Argus1 camera but using a novel reduced body Pevicon tube, but still retaining the full 1" imaging area.
Several shutter designs were used to fit the evolving helmet mechanical constraints.
GB Solo later switched to use ISG sourced thermal cameras and are still going under the 'Halo' name.

   

Data Table for P4444
   
Sensing Method Pyroelectric effect in TGS crystal material. Temperature changes from the scene cause charge to build up / decay on the inner face of the target material.
Sensor Type / Size EEV 'Frogshead' Pevicon P8221/P8227 2/3" body with 18mm circular target area. Both 'soft' and 'hard tubes used.
Lens Parameters 18mm f/0/7 giving 50° field of view. Fixed focus by moving tube & yoke assembly at build
Dynamic Range / Control 60°C, automatic iris in lens
Display 38mm CRT with magnifier and mirror arrangement in helmet mask
Sensitivity (MDTD) <500mK
Power Source 10 'AA' cells. Normally LR6 alkaline, or optionally NiCd. Later models used ICOM radio battery packs, again 10 cells AA LR6 or NiMH
Power System Battery regulated to 8.7V in battery unit, camera ~4W. Modified P4428K battery unit (P4445) or later P4446 based on an Icom battery pack
Video Output BNC, produced in 60Hz / 525 line and 50Hz / 625 line variants
Image Processing Early models chopped by conical shutter, later used 3-blade shutter. Both with 1-field digital image store to give a constant image.
Manufacturer Status Obsolete, no longer serviced
Number and Years Built Around 100 from 1990 - 1993
Export Status Not controlled
Publicity Patent
   


The images above show how the camera image, on the usual 38mm CRT, was visible through an aperture in the facemask and then reflected from a curved mirror to give the user an image that was rather like a car dashboard. This was generally acceptable for all users, not needing adjustment.


This image is of the tube & scanning coils (yoke) arrangement for this camera. The narrow tube body allowed the overall yoke to be no wider than the 1" pevicon target diameter.

Back Home
Fire-TICs EEV P4444 Helmet Camera page 5 January 2016  All tradename © respective owners