The working principle of the float level gauge：an industrial tool for accurate level measurement

In the chemical, petroleum, water treatment and other industries, the float level gauge has become one of the core equipment for liquid level monitoring because of its simple structure, high reliability and strong adaptability. Through the principle of magnetic coupling and buoyancy balance, it converts liquid level changes into electrical signals to achieve remote monitoring and automatic control. This article will introduce the working principle, technical characteristics and application scenarios of the float level gauge in detail.

The core working principle of the float level gauge

Based on the Archimedes buoyancy principle, the float level gauge is mainly composed of a float, a guide rod, a reed switch (reed switch) and a signal converter, and its workflow is as follows:

1. Buoyancy: The float is suspended on the liquid surface according to the principle that the volume of the discharged liquid is equal, and moves up and down with the rise and fall of the liquid level.

2. Magnetic coupling conversion: The float has a built-in magnet, when the liquid level changes, the magnet is close or far away from the reed switch on the guide rod, so that its contacts are closed or disconnected, and the circuit resistance value is changed.

3. Signal output: The converter converts the resistance change into a 4~20mA standard current signal, and transmits it to the display instrument or control system to realize the digital monitoring of the liquid level.

Technical features of the float level gauge

1. High adaptability

It is suitable for high temperature (≤120°C), high pressure (0.6~2.5MPa), corrosive and viscous media (such as asphalt, wax-containing oil). It can measure conductive or non-conductive liquids, and is widely used in chemical, food, sewage treatment and other fields.

2. Stable and reliable

No mechanical transmission parts, reduce wear and tear, long life. Explosion-proof design (e.g. Ex ib IIB T4 certification) for use in flammable and explosive atmospheres.

3. Intelligent upgrade

Modern float level gauges integrate remote monitoring and support real-time data transmission and alarms.

Installation and maintenance points

1. Installation requirements

Maintain vertical installation to avoid the liquid inlet interfering with the float movement; For long measuring ranges (> 3.5 m), a support frame is required to prevent the guide rod from bending.

2. Common fault handling

Float stuck: remove iron filings or dirt adsorbed by the guide rod;

Signal Drift: Periodic calibration of zero and full scale.

With its simple and reliable operating principle, the float level gauge has become the cornerstone of industrial level measurement. Proper sizing and maintenance can significantly increase productivity and safety.

Note: This article is synthesized from the technical information of the industry, and the specific parameters are subject to the product manual.