The variable area flowmeter (VAF) or rotameter is one of the oldest and mature flowmeters in flow measurement with its simple design. A float rises inside a conically shaped glass tube as the flow increases and its position on a scale can be read off as the flow rate. The variable area flowmeter (VAF) or rotameter offers a broad portfolio includes armored metal, glass tube and plastic VAF's. The VAF is used for measurement of liquids and gases and is highly accurate, particularly for purging, analyzer and gas sampling systems, laboratories and machinery equipment. low flows and high pressure applications.