test instrument self diagnostic function

smoke detector tester for BS 5839 compliance direct from Wanlin Fire Protection — 12-year factory experience, WL-ST100 smoke detector tester certified CE/UL 268A/EN 54/NFPA 72/BS 5839/AS 1851. Key specs: Aerosol Dispersion + Adjustable Output + Telescoping Wand + Universal Test Cup, Manual Operation + Visual LED Indicator + Compatible with Solo/Testifire Ae···