The design and quality assurance of the VACOSS series production model

The production model of the electronic safeguards seal system VACOSS was developed and it quality assurance programme carried out under the Federal Republic of Germany programme in support of the International Atomic Energy Agency. The opening and closing of an optical fibre cable are controlled by a battery powered microprocessor. The electronic circuitry of the seal is surface mounted on two boards. A standard Li block battery has been chosen for reason of a service life of more than one year. Alternatively, a worldwide available standard 9 V block battery can be used, however, at the expense of a reduced service life. The coated electronic circuitry and the battery are contained in an injection-moulded casing. The interrogation and initialization unit has a 4 x 16 column alphanumeric liquid crystal display for user-friendly, menu-guided operation. A hardcopy of the display can be produced by connecting a printer. The seal has been qualified using military specification standards. An acceptance test programme was carried out using 8 seals. In addition, the seal electronics was subjected to in-circuit and burn-in testing.