Current Research Status of Metal Tube Rotameter Signal Acquisition Method

The metal tube rotameter is one of the widely used flowmeters. It has no risk of rupture of the cone tube. Compared with the glass tube float flowmeter, it has a wider temperature and pressure range. It has a simple and intuitive structure, small pressure loss, large measurement range, high operational reliability, and measurable small and medium flow rates. Reynolds number flow, easy maintenance, long life, low requirements for the length of the straight pipe before and after the instrument, etc.

The metal tube rotameter is divided into two types: local indication and remote indication. The local indication type directly indicates the flow rate through the pointer. The remote transmission type is divided into two types: air remote transmission and electrical remote transmission: the characteristics and structure of the pneumatic remote transmission float flowmeter are similar to those of the electrical remote transmission float flowmeter, except that the remote transmission signal is a pressure signal of 0.02~0.1 MPa, due to its output It is a standard air pressure signal, so it is suitable for explosive process, and can be used with pneumatic unit combination instrument for flow measurement and adjustment.

The current signal remote transmission method is still based on electrical remote transmission. The structure of the very commonly used electrical remote metal tube rotameter is based on the on-site indication type, and then drives the differential transformer or angular displacement through a specific mechanical structure. Sensors, etc., convert the position signal of the float into the angular displacement of the iron core of the differential transformer or the angular displacement sensor, etc., and then convert it into standard current and voltage signal output. The measuring devices generally use Hall elements, magnetoresistive elements and capacitive angular displacement sensors.