The Differences Between the Continuous Liquid Level Sensor and Point Liquid Level Sensor

When measuring the amount of liquid in a given container, many users choose to use a liquid level sensor. But which liquid level sensor should you choose? The choice of the liquid level sensor depends on the measuring environment and the liquid to be measured. This article will introduce different types of liquid level sensors and discuss their working principles.

1. Types of liquid level sensors

Firstly, we need to distinguish the functions of the liquid level sensor. Generally speaking, there are two main types of liquid level sensors: Continuous level sensors and point level sensors. For applications where continuous liquid level measurements are required, such as fuel tanks and storage tanks, the continuous level sensor can indicate the liquid level within the measuring range in a given container.

The other is the point liquid level sensor that indicates whether the liquid level is above or below a specific point. Usually, the point level switch is used as a warning indicator to trigger an alarm when the level is too high or too low, so as to hold the level between two points.

2. Introduction of point level sensor

Point level sensors have a wide range of types and are suitable for many applications and materials. A Float level sensor is a common point level sensor. Float liquid level switch is composed of a fixed rod and a floater; The floater has a built-in permanent magnet, which moves freely along the fixed rod with the rise and fall of the liquid level. The magnetic field of the permanent magnet acts on the magnetic reed switch, and the closer it is to the magnetic reed switch, the stronger the force is. When it reaches the threshold, the magnetic reed switch is closed. 

For the applications of point level detection requiring no moving parts, the optical liquid level sensor is a good choice. The optical liquid level sensor is suitable for high, medium and low liquid level detection, and is suitable for almost any installation mode. It has no moving parts and emits infrared light through the LED to calculate the liquid level change according to the amount of reflected light. Optical liquid level sensors can be customized to high temperature resistance models and are available in different sizes to meet the needs of different applications.

The point level switch, such as the RF admittance point level switch, can indicate a specific liquid level, but for continuous liquid level measurement and monitoring within a certain range, continuous liquid level sensors are required. Just like the above float and ultrasonic liquid level sensor technology, we can use a continuous float level transmitter or ultrasonic liquid level sensor for continuous liquid level measurement. In addition, potentiometric and magnetostrictive liquid level sensors can also be used for continuous level measurements.

When selecting a liquid level sensor, it is important to confirm whether the sensor or switch type meets the application requirements. In addition to the potential mechanism of action, it is also important to consider the viscosity of the material (especially when measuring the corrosive media) and the liquid to be tested.