How to choose a water level sensor for a tank: a complete guide
Liquid level control in reservoirs, tanks and other containers is a critically important task in a wide variety of fields: from industrial water supply and chemical processing to household autonomous water supply systems and aquaponics. Incorrect selection or sensor failure can lead to overflow, "dry running" of the pump, production stoppage or damage to the equipment. This article will be your comprehensive guide that will help you understand the variety of solutions, understand their principles of operation and, most importantly, choose a water level sensor for a tank that perfectly meets your specifications and budget. You will gain structured knowledge that will allow you to confidently conduct a dialogue with suppliers and engineers.
The main difficulty in choosing lies in the huge number of types of sensors, each of which has its own strengths and weaknesses. There is no universal solution that would work equally well in a plastic barrel with drinking water and in a steel reactor with aggressive acid. Our guide will help you navigate through this variety, focusing on the key parameters.: the type of medium being measured, the accuracy, the operating conditions and, of course, the cost of ownership.
The main types of level sensors and the principles of their operation
All sensors can be roughly divided into two large groups: contact (which directly interact with the environment) and contactless. The choice in favor of one group or another depends on the properties of the liquid and the conditions inside the container.
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Float sensors. The simplest and most cost-effective mechanical principle. The float with a magnet moves with the liquid level, closing or opening reed contacts. They are ideal for clean, non-viscous liquids in simple alarm systems (for example, monitoring the level in the well tank). Their main disadvantages are limited accuracy and sensitivity to contamination.
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Capacitive sensors. The change in electrical capacitance between the electrode (probe) immersed in the medium and the wall of the container is measured. They are versatile, have no moving parts and are suitable for liquids, suspensions and bulk materials. They require calibration for a specific medium, since its dielectric constant directly affects the readings.
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Hydrostatic sensors (pressure sensors). One of the most common and reliable methods for closed containers. The principle is based on Pascal's law: the pressure of a liquid column is directly proportional to its height. To accurately buy a pressure sensor https://owen.by/davlenie/preobrazovateli-davleniya.html To measure the level, it is important to understand