Industrial Tanks

Why choose Coltraco Ultrasonics’ range of Ultrasonic Tank Liquid Level Indicators

The portable and non-invasive design of the Portatank® allows liquid levels to be located through the side walls of tanks without the need for drilling or opening the tank, eliminating downtime. It is highly versatile, working on tanks with depths ranging from as small as 0.5 meters up to 15+ meters.

Additionally, the device is compatible with tanks made from various materials, including metals, plastics, and glass, regardless of wall thickness.

The Portatank® can measure virtually all liquids as long as they remain liquid, making it an ideal solution for tanks without existing liquid-level detection methods. Its accuracy makes it an excellent replacement for traditional level gauges, such as sight glasses or float level gauges, without requiring any modifications to the tank itself.

As a complementary tool, the Portatank® can periodically verify the accuracy of built-in level indicators, such as radar level gauges, float and sight glasses. It offers advanced diagnostics through a handheld oscilloscope with each unit, enabling precise calibration to the specific tank being tested, ensuring maximum accuracy, and assisting with troubleshooting.

The Portatank® is designed to be portable, allowing one instrument to be used across multiple tanks on the same site. It requires only a single operator and no installation costs, making it a cost-effective solution.

Additionally, with its portability, the Portatank® is ideal for use as an “interim” instrument when tanks are undergoing maintenance or while built-in level sensors are being refitted. This flexibility ensures reliable monitoring of liquid levels in tanks, regardless of tank depth or liquid type.

How does Coltraco Ultrasonics’ range of Ultrasonic Tank Liquid Level Indicators work?

All of our ultrasonic tank liquid level indicators use advanced ultrasonic level sensors to detect liquid levels within tanks accurately. Ultrasonic sensor technology, or Ultrasonic Testing (UT), is a reliable, versatile, and safe method for Non-Destructive Testing (NDT). It operates by transmitting ultrasonic waves—sound waves with frequencies above 20kHz, the upper limit of human hearing.

These sound waves are mechanical and travel straight through a medium. How sound waves propagate and attenuate depends on the medium’s atomic structure, making ultrasound a valuable tool for studying materials and their internal processes.

While humans can hear sounds up to 20,000 Hz, our ultrasonic tank liquid-level indicators utilise high-frequency ultrasound transmitters ranging from 200,000 Hz (200 kHz) to 2,000,000 Hz (2 MHz). The central unit sends an electrical signal with the correct voltage to the level sensor containing a piezoelectric crystal. This crystal converts the electrical signal into a high-energy ultrasonic pulse transmitted into the tank wall, a process known as the reverse piezoelectric effect.

The ultrasonic waves travel through the tank’s solid walls and interact with the liquid contents. After emitting the ultrasonic pulse, the sensor listens for returning echoes. These echoes return to the sensor when liquid is present, allowing the instrument to indicate liquid presence via LED signals. If no liquid is detected, the echoes will not return, signalling an absence of liquid. This process, known as the “pulse-echo” method, enables the accurate detection of liquid levels.

Our ultrasonic tank liquid level indicators are designed to be compatible with other equipment and can be easily calibrated to ensure precise measurements, regardless of tank size or liquid type. With compact dimensions, these devices are easy to install and maintain, providing a reliable solution for monitoring tank levels across various applications.

Types of Application for Our Range of Ultrasonic Tank Liquid Level Indicators

Transformer / Ring Main Unit (RMU) oil level indication

The Portatank®, our handheld ultrasonic tank liquid level indicator, has been successfully used to detect fluid levels, such as oil, in various transformers and ring central units (RMUs).

In a recent test, the Portatank® was used on ring central units that were part of the Yorkshire switchgear distribution box. The oil tanks in the switchgear were approximately 35cm to 40cm in length and width. The Portatank® accurately identified the correct oil level in these tanks, and its readings were compared against a built-in mechanical level indicator. While the mechanical level indicator showed the tank as complete, the Portatank® detected the fluid level about 7cm below what the float gauge indicated.

The oil level identified by the Portatank® was later verified using a dipstick, which confirmed the Portatank®’s reading was precise. This demonstrated the limitations of mechanical indicators and highlighted the Portatank®’s accuracy and reliability in non-invasive fluid level detection. The device can also be calibrated using a calibration wire to ensure consistent results across various applications.

Additionally, the Portatank® is widely used by Power Generation companies worldwide to monitor oil levels in Single-Phase and Three-Phase transformers, with applications across multiple kVA ratings, including 19.9, 25, 50, 75, and 100 kVA.

Due to its non-invasive measurement method, the Portatank® allows transformers to remain operational (“live”) during testing, reducing the risk of introducing oxygen into the system. This is particularly important, as low oil levels in transformers can lead to combustion risks when oxygen mixes with excessive heat generated by the transformer.

Beyond oil detection, the Portatank® can also measure fluid levels in drinking water tanks, further showcasing its versatility across different industries and applications. The device meets the required specifications for a wide range of fluids, making it an indispensable tool for accurate, real-time level detection.

Key Measurement Considerations – Ultrasound Couplant

For the Portatank® to measure liquid levels reliably, it is essential to ensure sufficient ultrasound couplant is used. Ultrasound couplant, in the form of ultrasound gel, reduces the air pockets between the sensor and the tank wall and allows for efficient ultrasound transmission.

Our sensors for the range of ultrasonic tank liquid level indicators we manufacture, such as the Portatank®, work with almost any ultrasound gel. Medical ultrasound gel is cheap, widely available, and will work well with our instruments. For example, it can usually be purchased locally in your country in a pharmacy.

Key Measurement Considerations – Presence of Intrusive Structures

As described in previous sections, the measurement principle of our range of ultrasonic tank liquid level indicators is based on a “pulse-echo” methodology. This relies on the ultrasound transmitted from the sensor through the liquid, which is reflected off the opposite wall in your tank.

If internal structures are present in your tanks, our instruments, such as the Portatank®, can still work, as the ultrasound signal can still be reflected off your internal structures back to your sensor. Please contact us to discuss your application if you feel you have a challenging one.

More complicated structures, such as transformers, may be filled with internal structures of various shapes and sizes, which can cause the reflected sound waves to be inconsistent. In this instance, it is recommended to test on a section of your tank closer to the edges where you can obtain a clear pathway of ultrasound transmission through your tank.

The Portatank sensor is about 25mm / 1” comprehensive; therefore, for the measurement to be successful, you will only need a strip as wide as 25mm / 1”.

Speak To Our Team For Your Tank Ultrasonic Level Sensor Today!