Other Level Meters

Float Level Gauges (Mechanical Level Sensors)

Float level gauges are among the simplest and most affordable devices for measuring liquid levels. Their operation is based on the physical principle of buoyancy: a hollow float rests on the liquid surface and moves up or down following the level. Inside the device, the float is usually connected to a signal transmitter via magnetic coupling or a lever. For example, in modern models, the float liquid level sensor is equipped with a magnetic float that interacts with a sensor module, which converts the level change into a standard 4–20 mA current signal. Thus, the float level gauge can continuously transmit the current level value to a control system or indicator. This allows for remote monitoring without the need to visually observe the level.

Main advantages of float sensors:

• Firstly, they feature an extremely simple design and ease of installation. The device contains minimal electronics – it is essentially a mechanical level sensor with a single moving element (the float). This simplicity ensures high reliability and repeatability of readings.
• Secondly, float level gauges usually have a low price compared to more complex electronic devices. At the same time, their accuracy is sufficient for most tasks, and the error does not depend on the chemical composition or electrical conductivity of the monitored liquid.
• The float works equally well whether the tank contains water or oil – the density and dielectric properties of the medium practically do not affect its operation.
• Float devices do not create sealed entries into the tank and do not contain membranes, thus eliminating leaks and contamination problems of the sensor by the measured medium. Modern float liquid level sensors usually have a sealed housing and a high degree of protection (up to IP68), allowing them to operate submerged in liquid for extended periods.

Float level gauges are widely used. A classic float water level sensor can be found in water supply systems (level control in tanks and reservoirs, wells, boreholes), in treatment facilities, and sewage pumping stations.

Float sensors are popular in the petrochemical industry – for monitoring the level of fuel, oil, and petroleum products in tanks and cisterns. For example, many diesel fuel storage tanks use float fuel level gauges for continuous volume measurement.

Additionally, float level alarms (so-called FLDs – float level detectors) are often installed to protect equipment: they signal a minimum liquid level (protecting pumps from "dry running") or an overflow when the maximum level is reached.

Thanks to their reliability and simplicity, float level gauges are also in demand for household applications (e.g., float level control in domestic pumping stations, septic tanks, etc.). It should be noted that for correct operation of such sensors, a relatively calm surface state is desirable: strong fluctuations or splashes in the tank can cause jumps in float readings. Overall, a proper choice of design (size and shape of the float, damping of oscillations) allows float level gauges to be used in almost any liquid media, including aggressive and explosive ones.

Capacitive Level Gauges: Principle of Operation and Application

A capacitive level gauge is an electronic sensor that measures level by changes in electrical capacitance. It consists of a sensitive element (electrode or probe), converter electronics, and, if necessary, a housing or mounting.

The principle of operation of a capacitive level sensor can be described as follows: the measuring probe together with the tank wall (or a second electrode) forms a kind of capacitor. When the liquid in the tank rises or falls, it changes the dielectric constant of the space between the electrodes and, accordingly, their electrical capacitance. A special converter detects these capacitance changes and converts them into an output electrical signal proportional to the level. Thus, without any moving parts, the capacitive sensor continuously "senses" the current liquid level.

Features of capacitive level gauges:

1. This is a contactless method mechanically – the probe contains no moving parts and practically does not wear out.
2. The sensor has a fast response to level changes, which is important in dynamic processes.
3. The probe design can be made from materials resistant to aggressive environments (e.g., Teflon coating), so capacitive sensors are suitable for monitoring levels of acids, alkalis, petroleum products, and other chemically aggressive liquids. They are also successfully used where float or other contact methods are unsuitable – for example, under high pressure or temperature in the tank.
4. Installation and setup of such devices are quite simple: the probe is usually installed vertically in the tank (submersible version) or mounted on the side or top of the lid. There are surface capacitive level sensors that attach externally to the wall of a non-metallic tank and allow level measurement without direct contact with the liquid. This is relevant for toxic or food media where sealing is important.

Capacitive level gauges are versatile – they are used not only for liquids but also for monitoring levels of grain, powders, cement, and other bulk materials in silos. In gaseous media, capacitance changes can also be detected (e.g., determining the "liquid-gas" interface), although level changes in pure gas are irrelevant.

Capacitive level sensors are widely used:

• In industry. They are in demand in the chemical and petrochemical sectors – for continuous monitoring of reagent, raw material, and fuel levels in process tanks.
• In the water supply and utilities sector, capacitive level sensors are used to monitor water in tanks, reservoirs of clean and wastewater, and wells.
• In food and pharmaceutical production, this type of sensor allows measuring the level of liquid products, syrups, beverages, etc., without the risk of product contamination (when using hygienic probe covers).
• In agriculture. Capacitive sensors are used to monitor grain levels in elevators, feed in bunkers, and more.
• In the transport sector, they have proven themselves as capacitive fuel level sensors – many trucks and special machinery are equipped with capacitive fuel meters that provide more stable readings than simple float sensors.

Overall, the capacitive level sensor is convenient where durability, absence of moving parts, and high sensitivity are required. However, proper initial calibration according to the dielectric properties of the specific medium is important for correct operation. For example, if the liquid significantly changes its dielectric constant with temperature fluctuations, this can affect accuracy. Also, deposits on the probe (soot, adhesion of viscous media) can distort measurements – therefore, periodic cleaning or choosing a sensor with a self-cleaning coating is sometimes necessary. With proper selection and installation, capacitive level sensors provide reliable and accurate level control comparable to other modern methods. Their advantages – fast response, versatility, and long service life – make these devices among the most popular in the level measurement segment.

Where to buy float or capacitive level sensors: price and advantages

If you need a reliable liquid level controller, the company "Izmerkon" offers modern float and capacitive level sensors of our own production. We will help you select the optimal solution for your tasks – whether it is a simple float water level sensor for a tank or a high-precision capacitive level sensor with a digital interface. You can buy a float level sensor or capacitive sensor directly from the manufacturer at a favorable price. To find out the cost and order the device, just leave a request on the website or call us – our specialists will promptly consult and arrange delivery. Below are the main reasons why customers choose "Izmerkon":

• Professional expertise and experience. We have been developing and manufacturing sensors for over 15 years – our engineers have high competence and understand the specifics of level sensor applications in various industries. You receive expert assistance in solving your task.
• High quality of devices. All level sensors are made from reliable materials and undergo strict quality control. We offer modern level sensors with high accuracy and durability.
• Flexible pricing policy. Thanks to our own production and large supply volumes, we provide competitive prices. Regular customers have access to special conditions: discounts, individual payment and delivery options.
• Assembly in Saint Petersburg to order. Our level sensors are assembled at our own facility in St. Petersburg. This guarantees fast manufacturing times and the ability to customize the device to your requirements (non-standard probe length, output type, etc.). You get a solution perfectly suited to your operating conditions.
• Warranty and service support. All supplied level sensors come with a manufacturer’s warranty. We also provide post-warranty service, operational consultations, and repairs if necessary. You can be confident in the reliable operation of the equipment throughout its service life.

By ordering level sensors from "Izmerkon," you choose quality, professionalism, and favorable terms. Contact us today – and we will help you ensure effective level control at your facility!