1>flow meter,variable-area metallic rotameter 2> ... with simple structure,work reliable,wide application field,high precision,convenient installing,it is suitable for ... flowmeters,this series has the characteristics of high-pressureproof,high-temperature proof,safety,ocular reading etc,it ... Alarm switch:Solid-state relay,electric current 200mA,voltage 50V 7.Explosin-proof mark: Intrinsically safe type ...