The all-metal variable area flowmeter HF Series is used for flow measurement of conductive and non-conductive liquids, gases and vapours.  It's with small volume, wide range and easily operation.The flowmeter adopts variable area measuring principle.The measuring device is composed of one taper measuring pipe and float.The float can move freely up and down in the taper measuring pipe to change the folw area in the pipe. When the folw changes, the vertical position of the floater inside the measuring pipe changes correspondingly.Through magnetic coupling transmitting system,the position of the float is transmitted to the  scale of the indicator to indicate the flow.