Level gauges are devices used to visually or electronically measure the level of liquid in tanks or vessels. There are various types of level gauges available, each with its own operating principle, advantages, and applications. Here are some common types of level gauges and their applications:

1. Sight Glass Level Gauges:

   • Principle: Sight glass level gauges consist of a transparent or translucent glass tube or window installed on the side of a tank. The liquid level is visible directly through the sight glass.
   • Applications: Suitable for applications where direct visual observation of the liquid level is required, such as small tanks, low-pressure vessels, or applications with clear, non-hazardous liquids.

2. Tubular Level Gauges:

   • Principle: Tubular level gauges consist of a transparent or reflex glass tube mounted vertically on the side of a tank. The liquid level inside the tube corresponds to the liquid level in the tank.
   • Applications: Widely used in boilers, pressure vessels, and steam applications where high temperatures, pressures, or corrosive liquids are present.

3. Magnetic Level Gauges:

   • Principle: Magnetic level gauges use a magnetic float inside the tank, which rises and falls with the liquid level. External magnetic flags or indicators on the outside of the gauge move in response to the float position, providing a visual indication of the liquid level.
   • Applications: Suitable for applications with high temperatures, pressures, or corrosive liquids, such as chemical processing, oil and gas, and power generation.

4. Float Level Switches:

   • Principle: Float level switches consist of a buoyant float connected to a switch mechanism. When the liquid level reaches a predetermined point, the float triggers the switch, signaling the presence or absence of the liquid at that level.
   • Applications: Used for point level detection in tanks, vessels, and sumps in various industries, including water treatment, wastewater management, and industrial automation.

5. Displacer Level Switches:

   • Principle: Displacer level switches use a displacer or buoyant element suspended from a spring. As the liquid level changes, the displacer moves, causing the spring to stretch or compress. The change in spring tension actuates a switch mechanism.
   • Applications: Suitable for high-temperature, high-pressure applications and for detecting interface levels or specific gravity changes in liquids, such as oil-water interfaces in separators or interface control in storage tanks.

6. Ultrasonic Level Sensors:

   • Principle: Ultrasonic level sensors emit high-frequency sound waves that bounce off the liquid surface and are then detected by the sensor. The time it takes for the sound waves to return is used to calculate the liquid level.
   • Applications: Suitable for non-contact level measurement in tanks, vessels, and open channels in various industries, including water and wastewater management, chemical processing, and food and beverage.

7. Radar Level Sensors:

   • Principle: Radar level sensors emit microwave signals directed toward the liquid surface. The time it takes for the signals to reflect off the surface and return to the sensor is measured to determine the liquid level.
   • Applications: Suitable for non-contact level measurement in tanks, vessels, and silos with harsh environmental conditions, such as high temperatures, pressures, or vapor, commonly used in industries like oil and gas, petrochemicals, and mining.

These are just a few examples of common types of level gauges and their applications. The selection of the most suitable level gauge depends on factors such as the type of liquid, operating conditions, accuracy requirements, installation constraints, and budget considerations. Consulting with experts and suppliers can help determine the best solution for specific application needs.