One of China's most visited cultural sites: the Mausoleum of Qin Shihuangdi in the city of Xi'an needed a comprehensive security alarm upgrade. The UNESCO World Heritage Site is home to a 2,000-year-old army of clay statues, the world-famous Terracotta Warriors, guarding the tomb of China’s first emperor. The site is visited by thousands of people each day and call for an unobtrusive, yet effective intrusion detection system that reliably alerts security staff to potential incidents, while still allowing tourists to see the integrity of the site.

In order to protect the large site from theft, damage and vandalism, the museum installed a comprehensive intrusion system from Bosch Building Technologies. Several hundred TriTech motion detectors are deployed to protect the 16,300-square-foot museum against theft and damage. These detectors prevent false alarms under challenging environmental conditions, while providing detection reliability of real alarms.

As wall detectors, the TriTech motion detectors protect the pits where the terracotta warriors are located. Because these pits collect large amounts of dust that could cause false alarms, the sensor data fusion algorithm in each of the rugged detectors checks potential alarms with PIR sensor and microwave Doppler radar for a consistent result. The area to be protected is also secured from above by ceiling-mounted TriTech motion detectors. These detectors are located 4.8 meters above the museum floor, yet operate accurately and reliably. They thus exceed the range of standard ceiling detectors by more than two meters.

In the event of an actual security breach, the Bosch G Series system controller sends an alert, including the location of the triggered detector, in less than two seconds to the security team in the control room, which uses live images from a video system to verify the alarm. In most cases, tourists trigger an alarm when they cross a threshold to retrieve their cameras or smartphones that have accidentally fallen into the pit. In doing so, there is a risk of damage to the priceless terracotta warriors.