Why is My Ultrasonic Flow Meter Not Accurate?

Subscribe for the latest industry news, technologies and resources.

We care about your data in our privacy policy.

Do Ultrasonic Flow Meters Need Calibration? 

Ultrasonic flow meters are widely used in various industries to measure the flow rate of liquids. They offer many advantages, such as non-invasiveness, low maintenance, and high accuracy. However, despite their reliable performance, there are instances when ultrasonic flow meters may exhibit inaccuracies. In this article, we will explore some common reasons why your ultrasonic flow meter may not be accurate and discuss potential solutions to improve its performance.

Installation Issues

Proper installation plays a crucial role in ensuring the accuracy of an ultrasonic flow meter. Any errors or misalignments during installation can lead to inaccurate measurements. It is important to follow the manufacturer’s guidelines and recommendations for installation. Additionally, selecting an appropriate location away from disturbances such as bends, valves, or pipe irregularities is essential.

Transducer Problems

The transducers are the key components of an ultrasonic flow meter that emit and receive ultrasonic signals. Issues with the transducers can significantly impact accuracy. Common problems include air bubbles, dirt, or deposits on the transducer surfaces, which can interfere with the ultrasonic signal. Regular cleaning and maintenance of the transducers are crucial to ensure optimal performance.

Signal Interference

External factors can introduce signal interference, affecting the flow meter’s accuracy. Electrical equipment, nearby machinery, or electromagnetic fields can disrupt the ultrasonic signals. Shielding the flow meter from these interferences or relocating it to a less disruptive environment can help mitigate inaccuracies caused by signal interference.

Pipe Conditions and Material

The condition and material of the pipe through which the liquid flows can impact the accuracy of the ultrasonic flow meter. Irregularities in the pipe, such as corrosion, scaling, or rough surfaces, can cause signal reflections or attenuations, leading to inaccuracies. It is important to regularly inspect the pipe and address any issues promptly to maintain accurate measurements.

Flow Profile

The flow profile refers to the velocity distribution across the pipe’s cross-section. If the flow profile is not uniform, the accuracy of the ultrasonic flow meter can be compromised. Factors such as bends, valves, or obstructions in the pipe can cause variations in the flow profile. The flow meter’s accuracy can be improved by ensuring a smooth and fully developed flow profile.


Regular calibration is essential for maintaining the accuracy of any measuring instrument, including ultrasonic flow meters. Over time, factors such as transducer drift, ageing components, or changes in the process fluid can affect the calibration. Following the manufacturer’s guidelines for calibration intervals and ensuring proper calibration procedures is recommended.

Contact Coltraco Ultrasonics Today

Ultrasonic flow meters are reliable instruments for measuring flow rates, but they may experience inaccuracies under certain circumstances. By addressing installation issues, maintaining the transducers, mitigating signal interference, considering pipe conditions, optimising the flow profile, and conducting regular calibration, the accuracy of your ultrasonic flow meter can be significantly improved.

Visit Coltraco’s product categories page for more information on ultrasonic flow meters and their types. They offer a range of ultrasonic flow meters suitable for different applications. Additionally, you can learn about the two types of ultrasonic flow meters, namely Doppler and transit-time, on Coltraco’s page. To better understand ultrasonic flow meters, visit Coltraco’s page explaining the concept and working principles behind ultrasonic flow meters.

Remember, accurate flow measurement is crucial for various industries, and by addressing the potential issues mentioned in this article, you can enhance the accuracy and reliability of your ultrasonic flow meter.

Get in touch

You can reach us anytime via phone or email, we aim to respond to all enquiries within 24 hours (excluding weekends and bank holidays)


Come say hello at our Technical Laboratory.

Coltraco Ultrasonics
NETPark Research Institute
Joseph Swan Road
TS21 3FB

United Kingdom


Monday - Friday (excluding bank holidays) from 8:30am to 6:00pm, UK.

Tel (Sales & HQ): +44 20 7629 8475
Tel (Technical): +44 1740 618 240