This solution enables the implementation of an “impartial” control system which acts as a strong deterrent against pilfering within the area to be protected. The unit receives as an input a transit request coming from an access control reader, a button or a system of photocells and decides autonomously whether it should grant access or ask for the user to be checked. The system is called impartial because it decides in a fully autonomous and random way to block the transit of a user requiring access in order to carry out the control procedure. The parameter on which the impartial system is based is a random generator which simulates the extraction from a container of a black ball out of “X” red balls. The value of “X” is defined as the coefficient of the impartial system.
The solution is usually connected to a physical gateway which blocks transit in case of a request for control of a user and activates an alarm system, but a solution which does not require a physical gateway is also possible, with a photocell system which can detect incoming or outgoing transit. The impartial system may only function in one of the two directions (usually on the way out, to carry out a spot check on the users). Since there is no physical hindrance to stop transit, especially in case of high flow, surveillance personnel will have to be alert if the flashing siren device is triggered in order to know who must be checked.