A modified design of a flow transmitter using rotameter as a primary sensor and LVDT as a transducer

Rotameter is one type of the variable area flow meter in which the height of the float is linearly related to the flow rate of liquid. It is generally used for measurement of flow rate of liquid and for display. The Rotameter gives the information about flow rate locally. In this paper an attempt has been made to transmit the information to a remote receiver. Float variation according to flow rate has been converted to an electrical voltage signal, the voltage signal amplified and transmitted to remote indicator. For generation of voltage a non-magnetic straight thin cylindrical rod has been taken whose one end is connected to float of Rotameter and the other end connects with the core of an LVDT. When float varied according to the flow rate of the liquid then core of LVDT also varied and generated voltage. It has been observed that movement of float as well as core and variation of LVDT output voltage has good linearity and repeatability. The necessary theoretical equations, along with the experimental results, are reported and compared in this paper.