ultrasonic flowmeter

[Charbel]

dear,

i was looking at the ultrasonic flowmeter from E+H, proline prosonic flow 93W, this flowmeter will be used for sewage applications, and the sewage as fluid and the lining are not indicated in the attached (att#1)

Do i need to order DDU18 for measuring the required sound velocities and DDU19 for measuring the required wall thickness for getting the proper values to configure this flowmeter? and how this is usually done?, are the measurements from DDU18/DDU19 used only one time and the result is input in the device?... please advice.


thanks a lot!

charbel

 

[Tom Jenkins]

Solids content in sewage varies significantly, from negligible in treated effluent to several percent in return sludge.

Wastewater is a large field of application for these flow meters. I suggest you contact E+H for application assistance.

As a side note, you have to be careful with clamp on flow meters. I have had mixed results with them in the past. I expect newer units are superior to the ones I used, but accuracy may not be as good as other types. Again, application assistance from the supplier is encouraged.

 

[danw]

The list of media you provided is typical of a transit time ultrasonic flow meter - 'clean' fluids with little or no suspended solids or bubbles. Flow measurement by transit time in sewage is very iffy, that's why it doesn't show up on the list.

Depending on where in the treatment stream you want to measure, a transit time clamp-on has a high probability of not working because of suspended solids. Suspended solids freak out a transmit time meter. A transit time meter needs to see all of the ultrasonic signal at the receiver, not have a large amount of signal dispersed by reflection off solids. Suspended solids are the domain of doppler flowmeters, not transit time.

My opinion is that transit time can be a very accurate flow measurement (when it can make the measurement), doppler is merely a relative magnitude flow indication with no bearing on being able to relate the flow to an absolute. But that's my opinion.

Pipe wall thickness is usually taken from a chart since the pipe schedule/construction is usually a known. The assumed sonic velocity is the sonic velocity for water, which the meter should know. So no, you shouldn't need a wall thickness measurement instrument nor anything to determine sound velocity.

If I were you, I wouldn't consider a purchase without first actually trying one on the dirtiest line you need to measure.