Dear all,

Your discussion are VERY interesting for me.

I need help/idea "how to detect dead waterline pipes/part of pipes" in building's. Especially in large business buildings, as hospitals, shopping malls etc.

Ultrasonic flow meter was my idea, too. But this stuff are so expensive, that it is hurt.

Tank you ,

Kind regards,

Vojislav

 

Hello,

You just hijacked an old existing thread:
http://forum.allaboutcircuits.com/showthread.php?t=26620

Now you have a thread of your own.

Bertus

 

What exactly constitutes a dead water pipe? If there is no water flowing in that pipe when all taps are open?

 

From http://www.globalw.com/products/FM500.html

How The Ultrasonic Flow Meters Work
The Sonic-Pro series Hybrid Ultrasonic Flow Meters can measure fluid flow in virtually any fluid in which sound waves can travel. The Ultrasonic Flow Meters are considered "hybrid" because they can measure fluid flow using either the Doppler or Transit Time methods. The Sonic-Pro ultrasonic flow meter's sound transducers are clamped to the outside of the pipe wall and include no moving parts. This method of flow measurement is safe, non-intrusive and very easy to service. The Ultrasonic Flow Meter's Doppler measurement method requires particles be present in the flow stream to "reflect" the sound waves. The ultrasonic flow meter may not read flow correctly when using the Doppler mode if the fluid contains no particles. The Ultrasonic Flow Meter's Transit Time measuring method requires relatively "clean" fluid to enable the sound waves to complete their circuit. The Ultrasonic Flow Meters may be operated in the Transit-Time mode when the fluid contains particles. To allow for changes in the fluid's particle count, the Sonic-Pro Ultrasonic Flow Meters monitor the signal gain and employ an Automatic Gain Control (AGC) algorithm that periodically adjusts the gain to maintain the optimum power level.

To measure phase shift(Doppler) @40kHz and/or speed of sound would require somewhat advanced PLL, ADC, and processor power.

Considering the breadth and depth of knowledge needed to create a non-contact fluid speed sensor is a project that even experienced designers would find a tad daunting. Parts cost alone would be a good fraction of the cost of a commercial unit for a one off prototype, which may not work in a fully reliable/accurate way.

 

http://www.dowsers.org/