Rotameter

Felix Meyer founded the company "Deutsche Rotawerke GmbH" in Aachen recognizing the fundamental importance of this invention.

Kueppers invented the special shape for the inside of the glass tube that realized a symmetrical flow scale.

In many other countries the brand name Rotameter is registered by Rota Yokogawa GmbH & Co. KG in Germany which is now owned by Yokogawa Electric Corp. A rotameter consists of a tapered tube, typically made of glass with a 'float' (a shaped weight, made either of anodized aluminum or a ceramic), inside that is pushed up by the drag force of the flow and pulled down by gravity.

If the tube is made of metal, the float position is transferred to an external indicator via a magnetic coupling.

This capability has considerably expanded the range of applications for the variable area flowmeter, since the measurement can observed remotely from the process or used for automatic control.