When selecting a perimeter security product, security professionals should focus on the following performance criteria: detection rate (PD), false negative rate (VD), false positive rate (FAR), and false positive rate (NAR). These standards fully reflect the strengths and weaknesses of different products. Full understanding of these four indicators is the key to choosing the right technology for an application.

Detection rate: PD is expressed as a percentage, that is, the probability that the detector detects intruders in the zone. The detection probability of the detector is influenced by the characteristics of the target object (such as quantity, volume, speed, and direction), sensitivity device, weather conditions, location conditions, and regular maintenance of the instrument. The detection rate can reach 100%, but it will be accompanied by a very high rate of false positives. The probability of detection of outdoor detectors is usually specified as 99%, any less than 95% is not considered. (The detection probability of 95% means that there is one out of every 20 intrusions.)

Missed report rate: VD is also expressed as a percentage, that is, the probability that the detector cannot detect the intruder in the zone. This is an indicator corresponding to the detection rate. In the security industry, the missed report rate is a very important indicator. Generally, it is not considered if it exceeds 3%.

Misstatement Rate: Misstatement refers to false alarms caused by unknown reasons. The alarm caused by the noise generated by the detector itself is the most typical misstatement. In addition, the electronic components of the detector may exceed the temperature limits that may be tolerated, poor grounding, incorrect wiring connections, power supply voltage fluctuations, instrument damage during installation, and improper detector maintenance. The misstatement rate is usually expressed as the number of occurrences per day/month/year of each zone. The misstatement rate is generally negligible, low-grade detectors misreport once a month, and high-end products once a year.

False alarm rate: false alarms are false alarms caused by non-threatening identifiable causes. The false alarm rate is also expressed as the number of occurrences per day/month/year of each zone. Unlike FAR, the NAR alarm cause can be determined by the system operator and can be recognized by the remote CCTV. Most of the false alarms are related to small animals, or affected by the environment (such as wind, rain, snow, fog, hail, day/night, etc.) or topographical conditions. Vegetation factors and non-threatening personnel walk around the defense zone. The rate of false positives depends on the technology, practical application, and site conditions. The high-end detectors usually have a false alarm rate once a month, and low-grade detectors once a day. According to the security requirements of different sites, security experts determine the acceptable rate of detection false alarms in specific situations.

From an objective and scientific perspective, it is impossible to achieve a zero false alarm rate in any application. As a security practitioner, one cannot use “zero false positives” to mislead the market. Proper misstatements and false positives are necessary for the effectiveness of the perimeter protection system.

In specific applications based on site environment, user budgets, and security assessments.