A modern-day vape detector can run on battery power

https://markets.businessinsider.com/news/stocks/zeptive-releases-update-1-33-500-for-vape-detectors-adds-enhanced-detection-performance-loitering-monitoring-and-integrations-with-bosch-milestone-i-pro-and-digital-watchdog-1036055200

A modern vape detector can run on battery power, enabling flexible placement in restrooms and locker rooms without costly circuitry or restorations.