Introduction: Why correlation is crucial for leak detection.
If there is a leak somewhere in an underground drinking water network, water engineers and service providers often have a challenging detective job on their hands. This is where correlation comes into play - a proven method for pinpointing leaks. But what exactly does correlation mean, how does it work and how can modern technologies such as the HL 7000 or SmartEAR® from SebaKMT® can make this process efficient and reliable?
What does correlation mean?
In leak detection, correlation refers to the evaluation of transit time differences of sound waves emanating from a leak. A leak generates characteristic noises that spread through the pipe system. With the help of sensors - known as correlators - the sound is recorded at two points in the pipe.
The basic idea
- The sensors measure when the leakage noise pulse arrives.
- The exact leak position is determined from the transit time difference and the known speed of the sound in the pipe material.
- The result: pinpoint leak detection without unnecessary digging.
Important factors influencing accuracy
The quality of the correlation depends on various factors:
- Pipe material and diameter: Sound propagates differently in plastic pipes than in cast iron.
- Distance between the sensors: The greater the distance, the more accurate the calculation can be - up to a certain limit.
- Leak noise quality: If the leak noise is very quiet or superimposed, the probability of detection decreases.
Tip: The use of intelligent devices such as SmartEAR®which use modern sensor technology and intelligent algorithms to reliably detect even quiet leakage noises.
When should you use correlation?
Correlation is particularly suitable for:
- Buried pipes where acoustic localization with a ground microphone is difficult.
- Long distances where precise monitoring of every point would be inefficient.
- Night-time use where ambient noise is low.
In combination with pre-location using noise loggers such as SmartEAR® or acoustic monitoring via POSEYEDON®, correlation can be used in a targeted and efficient manner.
Products that support you with correlation
🔍 SmartEAR®
Ideal for permanent noise monitoring in drinking water networks. Works with NB-IoT / LTE-M and sends the data encrypted to the POSEYEDON® cloud.
Advantage: Early detection of leaks and targeted correlation applications thanks to the localization focus.
🎯 HL 7000 Correlator
The premium device for precise leak detection using correlation - with touchscreen operation, GPS, automatic data analysis and optional extension for ground microphones.
Tips from the field
- Avoid vibrations: Place sensors in a stable position to avoid interference noise.
- Enter pipe data correctly: Material, length and diameter have a significant influence on the calculation.
- Carry out comparisons: If necessary, repeat measurements from another direction for confirmation.
Conclusion: Correlation - precise, efficient, indispensable
SmartEAR - IoT noise/frequency loggerForwater managers and service providers, correlation offers a scientifically sound but practical method for locating leaks in the drinking water network quickly and accurately. With modern devices such as the HL 7000 and the SmartEAR® in combination with the POSEYEDON® cloud solution, leaks can not only be found, but proactively avoided.
💬 Would you like to find out more or receive individual advice?
Feel free to contact us - we will help you find the right solution for your challenge.
FAQ on correlation
What is the difference between correlation and ground microphony?
Ground microphony actively listens to the noise above the ground, correlation passively calculates the leak from signals in the pipe system.
How long can the distance between the sensors be?
In practice, correlators work for distances of up to 600 m - depending on the pipe material and leakage noise.
Can I also use correlation at night?
Yes, the conditions are often optimal at night - less noise and clearer signals.