Each technology has its own timer, its activation opens a time window, during which the device waits for confirmation of an alarm from the other technology. In the case where an offender is approaching a guarded perimeter, he activates the microwave field together with the period, for example, of two minutes, during which he also has to interrupt infrared rays. If interrupted, i.e. when entering the protected area, the alarm output is activated, the infrared technology acts as a confirmation of the previous microwave alarm. If the microwave is accidentally activated by IM interference, the time window opens, but because the offender is missing and IM interference does not cause an alarm with infrared rays, the time window closes after two minutes, without a false alarm. In simple terms each technology has its own pros and cons, but as an trigger is required from both technologies to activate an alarm, then a more effective system is achieved.

Absolute Dual barriers can easily be set for high sensitivity for the microwaves if we place the infrared beam at a low-lying level in order to achieve a high level of security without false alarms. If an accidental false alarm of the microwave occurs five times a day, a two-minute time window is always open, in total 10 minutes a day. During this time, a false alarm would have to be set even in the infrared system in order to activate the “real” false alarm. Ten minutes, that is equivalent to six times per hour times 24 hours, which would result in one or two real false alarms in 144 days, which is 2 to 5 per year. Of course the worst case scenario has been used for this calculation, so in reality the number of false alarms would be lower.

Absolute Plus dual technology barriers have a range of up to 200m using DSP processor for signal processing, threat assessment, overall barrier control and its adjustment, and are equipped with a six-beam optical system, each system is a receiver as well as a transmitter. Three beams are pointing in one direction, the other three in the opposite direction. These six beams are considered as one beam, so even with a glare from the rising or setting sun at least three beams are always working. According to Sicurit there are not many dual barriers on the market, that can handle such angles and direct light from the sun, and that is why these systems have proved to be an ideal solution for perimeter security in solar power plants.