How Accurate Are Level Switches?

The accuracy of a level switch depends on its type, design, and application. In general, modern level switches are highly precise and can detect level changes with millimeter accuracy in some advanced models. Traditional analog level switches provide reliable precision for basic on/off functions, while digital variants can deliver detailed and highly accurate measurement data.

Factors Affecting the Accuracy of Level Switches

The accuracy of a level switch is influenced by several factors, including the technology behind the device, its application, and the installation environment. Below are some key considerations:

Type of Level Switch

Mechanical level switches, such as diaphragm-based models, are highly reliable for indicating when a specific level is reached but do not measure continuous levels.

Digital level switches, on the other hand, are equipped with sensors that provide continuous measurement values with high precision.

Material Properties

Level switches used for granular materials, powders, or liquids may have varying accuracy depending on the density, flow characteristics, and particle size of the material. For example, diaphragm switches like the NV 14P and NV 10P from Level Switch Sweden can accurately detect pressure changes from heavy materials such as grain, pellets, and sand.

Environmental Conditions

Accuracy can be affected by temperature, pressure, and humidity in the surrounding environment. Level switches constructed with temperature-resistant materials, such as oil-resistant nitrile rubber and nickel-plated brass, perform better under varying conditions.

Mechanical Diaphragm Switches: Sufficient Accuracy for Most Applications

Diaphragm switches, such as those in the NV series, have an accuracy that is well-suited for indicating specific levels in silos and transport systems. These switches are designed to activate with small diaphragm movements, typically within a range of 3–4 mm. This makes them ideal for preventing overfilling and signaling when a set level has been reached.

For example, the NV 14P model includes a compensation diaphragm that ensures pressure changes do not affect its accuracy, which is crucial when mounted directly on a container wall.

Digital Level Switches: Increased Precision and Real-Time Measurements

Digital level switches offer higher accuracy and are particularly useful for applications requiring continuous measurements. With sensor technology, they provide precise measurement values, monitoring level changes with millimeter accuracy or better. Additionally, they can transmit real-time data to monitoring systems, making them ideal for advanced process automation.

To ensure a level switch functions as accurately as possible, consider the following:

The level switch must be mounted correctly according to the manufacturer’s specifications. For models like the NV 14P, this may include using the appropriate type of flange and ensuring the compensation diaphragm is properly connected.

Dirt or dust can affect the movement of diaphragms or the accuracy of sensors. Regular cleaning and inspection are essential.

Choose a level switch suited to the properties of the material and the environment where it will be used. For example, a level switch with an IP65 enclosure is suitable for dusty or humid environments.

Summary

The accuracy of a level switch varies depending on its technology and application. Mechanical level switches provide sufficient precision for most industrial applications, while digital level switches offer advanced accuracy and real-time data. By selecting the right level switch for your application and ensuring proper installation and maintenance, you can maximize its performance and precision.