test equipment calibration interval

OEM smoke detector tester 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 Aerosol Cans. Bluetoo···