Non-contact level meters

When the non-contact level measurement method is applied:

• If the environment is aggressive (acids, alkalis) or toxic, and sensor immersion is dangerous for equipment and personnel.
• If the product is very viscous, sticky (oil, syrup, resins) – contact sensors quickly fail due to contamination.
• At high temperatures or pressures in the tank, unacceptable for float or other contact devices.
• In conditions of heavy dust, foaming, vapor formation – when ultrasound or optics may work unstably, the radar method provides a reliable result.

Radar Level Meter

Radar level meters emit electromagnetic waves in the gigahertz range and measure the time of their reflection from the product surface. Simply put, the principle of operation is similar to a radar: the device sends a short radio signal downward and then captures its reflection. The distance to the material is calculated based on the delay or frequency shift (FMCW method).

A modern radar level meter can accurately measure the level of both liquids and bulk materials, practically regardless of the properties of the medium (density, dielectric constant, etc.). The devices operate stably over a wide range of temperatures and pressures where other methods fail. For example, they are unaffected by high pressure under the tank lid, intense heating up to hundreds of degrees, or corrosive environments.

Radio waves respond weakly to dust or foam, so radar level sensors are successfully used in dusty silos, foamy drains, and other challenging conditions. They also have a minimal "blind zone" and can cover a very wide range – some models measure levels up to 30–50 m and more. For large tanks (oil storage, grain elevators), the radar method is often unrivaled.

It is common to distinguish between pulse and continuous (FMCW) radar level meters. In the first case, the sensor periodically emits short radio pulses and records their echo; in the second – it emits a continuous signal with smooth frequency modulation. FMCW level meters are considered more modern: they better measure solid materials of any size, are insensitive to gas "cushions" and dense dust in the container.

In industry today, there is increasing demand for high-frequency radar level meters (for example, with frequencies of 26 GHz or 80 GHz): the higher the signal frequency, the narrower the directivity pattern and the higher the measurement accuracy. Devices in the 76–81 GHz range (millimeter waves) can show levels with an accuracy of up to 1 mm, allowing their use even for calibrating measuring tanks. At the same time, the narrow beam (about 3–5°) facilitates installation in tanks with interfering internal structures, and the small dead zone (a few centimeters) allows monitoring of almost the entire tank.

Main advantages of radar level meters:

• high accuracy
• reliability.

They have no moving parts, require almost no maintenance, and provide stable readings even in extreme operating conditions. A radar sensor will successfully measure the level of aggressive acid in a closed container, molten metal in a furnace, or gasoline in a pressurized tank – tasks where other level control methods are simply inapplicable.

Ultrasonic (Acoustic) Level Meter

Ultrasonic level meters use high-frequency acoustic waves (ultrasound) to measure levels. The sensor emits a series of short sound pulses and receives the echo signal reflected from the surface of the liquid or material. Upon receiving the echo, the electronics calculate the distance based on the sound travel time, similar to an echo sounder.

Thus, the device non-contact "probes" the medium with an acoustic signal. The ultrasonic level meter is suitable for most liquids, including viscous ones, as well as some bulk products (powders, granulates).

Its accuracy is usually about 0.5–1% of the full range, and the maximum measurement range reaches 5–15 meters (depending on the model).

The advantages of ultrasonic technology are relatively low cost and simplicity of the devices. Installation and setup of the ultrasonic sensor are straightforward – just attach the transmitter at the top of the tank and connect the power supply. Additionally, such a level meter does not require contact with the product, which is important for cleanliness and safety, and thanks to the vibrations of the emitter membrane, ultrasonic sensors have a self-cleaning effect on the surface and are less prone to buildup formation.

Many modern ultrasonic level meters are equipped with digital indicators, protected against overvoltage, have a durable sealed housing (IP65/IP68), and withstand exposure to chemically aggressive vapors.

However, the ultrasonic method has limitations:

• The devices are sensitive to external conditions since sound propagation depends on the medium. For example, significant fluctuations in temperature or air pressure in the tank can affect measurement accuracy (although most devices have temperature compensation).
• Vapor formation. Strong turbulence or dense foam on the liquid surface can dampen or distort the ultrasonic signal. For this reason, ultrasound is usually not used for boiling liquids, and its capabilities are limited when measuring solid bulk materials – especially coarse fractions or heavily dusty media.
• They have a large "dead zone" near the sensor (several tens of centimeters from the emitter, where measurement is impossible) and a shorter range compared to radar.

Nevertheless, in conditions where the medium does not create strong acoustic interference, ultrasound provides quite sufficient accuracy and response speed.

These devices are widely used for monitoring the level of water, petroleum products, wastewater, solutions, and other homogeneous liquids in both open and closed tanks. Due to their more affordable price, ultrasonic level meters are often chosen as a budget solution for standard level measurement tasks.

Level Meters for Industrial Tanks and Vessels

Non-contact level meters have become common in almost all industries. They are installed on tanks, containers, cisterns, and silos of various purposes:

• In the chemical industry, radar sensors monitor the level of acids, alkalis, and reagents in process vessels.
• In the oil and gas sector, no storage facility for oil, gasoline, or liquefied gas operates without radar level meters – they are used for raw material and product accounting, overflow signaling, and pump control.
• At food and pharmaceutical enterprises, ultrasonic and radar level meters provide level measurement in tanks with food liquids (oils, syrups, milk, etc.), as well as raw material control in silos (flour, sugar, grain). Devices that do not contact the product itself are easier to maintain hygienically and do not violate sanitary requirements.
• In energy and metallurgy, wave level meters are widely used for complex media – for example, for high-temperature melts, slags, coal dust.
• In water supply and sewage systems, ultrasonic level meters are popular due to their simplicity and reliability: they are installed on water towers, settling tanks, open channels, and wells.

Thus, level meters in tanks of any type allow automating content control and ensuring safe equipment operation. A properly selected non-contact sensor will provide accurate level measurement in your vessel regardless of its size and product properties.

For each vessel, it is important to consider several factors – the material and aggregate state of the product, the height and shape of the tank, the presence of internal partitions or agitators, temperature and pressure ranges. For example, an ultrasonic level meter can be chosen for a 2–3 meter high water tank, while a radar sensor is definitely needed for a 20-meter silo with cement.

Experienced specialists know which type of device is optimal in each case, so when solving non-standard level measurement tasks, it is useful to consult our experts by phone or leave a request for feedback.

Buy a Level Meter: Price and Selection

The company "Izmerkon" manufactures and supplies various level measurement devices, including radar and ultrasonic level meters. You can buy a radar level meter for any application from us – from compact sensors for small vessels to high-frequency level meters for tank farms.

If maximum accuracy and stability are required under complex environmental parameters, purchasing a modern radar device is justified. For typical tasks (for example, water in an atmospheric pressure tank), an ultrasonic level meter will suffice.

The cost is determined by the model’s characteristics – operating range, explosion protection, radar frequency, antenna window material, and other options. We focus on the customer’s needs and help select the optimal level sensor for a specific task.

Current prices are available by phone – contact us, and we will promptly advise you on availability, cost, and delivery terms.

Our engineers are ready to answer any questions and provide technical support during installation and setup of the device. With modern non-contact level meters, level control in tanks becomes simple, accurate, and reliable.