test equipment calibration interval

carbon fiber telescoping pole direct from Wanlin Fire Protection — 12-year factory experience, WL-ST200 smoke detector tester certified CE/UL 268A/EN 54/NFPA 72/BS 5839/AS 1851. Key specs: Aerosol Dispenser + Heat Source + Dual Test Mode + Telescoping Wand, Manual Operation + Dual Function Switch + LED Indicators + Compatible with Standard Aerosol Cans. Blu···