Dribble rate sensor.

[itsmoked]

I'm finding it extremely hard to find a flow meter good for the area around the 0.01~0.2 gallon/minutes(150psi). [~6 fluid oz/min]

I've searched high and low.

I'm amazed places like GEMS have not addressed this region.

I'm starting to think I have to design one... Right after I kill myself.

~$200 limit.

Names?


Keith Cress
kcress -

http://www.flaminsystems.com

 

[ScottyUK]

What fluid are you metering? Positive displacement meters like oval gear or roots meters are pretty good on the more viscous liquids like oils and paints if they are free of solids.


----------------------------------

If we learn from our mistakes I'm getting a great education!

 

[itsmoked]

Sheesh.. No star for this question..

Water. Tap water...

Lots of those turbine meters out there. They just all krap out below 0.1gal/min. If they'd just make one fifty percent smaller we'd have it.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[danw2]

Dwyer rotameter (variable area floating ball)

http://www.dwyer-inst.com/Products/TOC.cfm?MainCategory_ID=3&iCurrentCategoryID=323

 

[jmw]

Rotary drum meter - good for drip flows.
This is a bit like a rotating multi compartmental bucket. In flow is directed into a a compartment to one side of the axis of revolution.
As it fills, it rotates the shaft until the next bucket is lined up and the first can drain away.

It might be similar to this:

http://www.freepatentsonline.com/4613058.html

but without the pics couldn't say.

It is a bit like this gas meter:

http://images.google.co.uk/imgres?i...rg.mozilla:en-US:official&sa=N&start=162&um=1

I think they were originally designed for some very slow process operations like condense flow from an evaporator or distillation column.


JMW

http://www.ViscoAnalyser.com

 

[jmw]

PS I take it you've investigate the very low flow rate coriolis meters and the new low flow rate Ultrasonic meter from FTI...

http://www.ftimeters.com/products/ultrasonic_flowmeters/ulf100.htm

but these all have a starying flow that may be too high?

JMW

http://www.ViscoAnalyser.com

 

[jmw]

Er, best to think of the drum meter like a water wheel and the way it rotates as the buckets fill and empty...

JMW

http://www.ViscoAnalyser.com

 

[roydm]

Why not a Mag meter
0.3" (8mm) 0.009 to 6.6 gpm
Roy

 

[roydm]

Or better yet a 0.15" (4mm) mag meter 0.002 to 1.6 g/m
0.6 ft/sec at 0.01 g/m
3.75 ft/sec at 0.2 g/m

 

[itsmoked]

Whoa, whoa ponies.. Did we miss the ~$200? I can't believe those mag meters or ultrasonics don't exceed this price by half a magnitude.

This is for embedding into a product that will likely be plumbed with 1/8" or 1/4" stainless steel tubing.

jmw; Those Flow Technology sensors look really nice. Not even their reps have prices... Doesn't bode well.

danw2; Thanks for the Dwyer link. They have a nice unit that's about $250 that could work. I wish I could dial down the price by dialing down the accuracy. I'm happy with about 2~3%.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[jmw]

The FTI US meters are relatively new.... but I guess the price is going to be pretty high...>$200.

So, back to a low cost meter...you didn't say if it is flow total or flow rate but if I assume flow rate, try a variable area flow meter.
These can be had for a few dollars if you don't need too great an accuracy.
Try Platon or Rotameter (now part of Emerson I guess...oops! Emerson appear to have discontinued the Rotameter VA meters.... and they were a top quality product...) so do a search for Variable Area meters.


JMW

http://www.ViscoAnalyser.com

 

[FrancisL]

How about a peristaltic pump?
A Search for "low flow peristaltic pump" produces plenty of results, some with prices.

 

[itsmoked]

jmw; Ah.. now that might be the ticket. I've seen those before. I didn't know that's what they were called. They make sense now. DOH!
Now if I can just find an electrificated one.

FrancisL; I'm afraid a peristaltic pump wouldn't have the lifetime needed since this thing will run thousands of cycles/day. Aren't PPumps really hard on their wetted element?

Keith Cress
kcress -

http://www.flaminsystems.com

 

[FrancisL]

Not sure about peristaltic pump tube lifetime so I would ask a supplier.

 

[roydm]

You said you wanted a flow meter, now you are talking about pumps.
Solenoid type metering pumps can have a very low overall flow rate.
There are other very low flow metering devices such as Clarkson feeder.
Perhaps give us some more details on what you are trying to do.
Regards
Roy

 

[FrancisL]

Itsmoked wanted a flowmeter and I started talking about pumps!
Perhaps that is a red herring, but the reason I brought it up was that many years ago I was involved in a project which needed a very low flow the speckler - for spraying ink onto mini eggs! And the solution we found was a peristaltic pump.
As ever a better understanding of the process is needed, for example what is the water for and what does actually set the flow rate.

 

[JimCasey]

Emerson didn't discontinue the VA flowmeter. The brand name is Brooks. Dwyer make cheapie injection-molded acrylic meters for about $50, but so do Brooks.
Here's a link. And no, I have no affiliation.

http://www.brooksinstrument.com/category11.asp

Pay a little extra for the integral valve and you can regulate the flowrate from the meter.

 

[jmw]

Sorry, they discontinued the Rotameter (a trade name and not a generic for a VA meter) manufactured originally by Rotameter, a part of GEC Automation, then Fisher Controls, then KDG, then KDG Mobrey and then Solartron Mobrey.
The next corporate shenanigans lead them to Emerson and on Emerson's Mobrey site you will see them under discontinued products.

JMW

http://www.ViscoAnalyser.com

 

[roydm]

Just looking through the Cole Palmer catalouge, they have a pelton wheel sensor in several low ranges
13 - 100 ml/m K-32703-50
50 - 500 ml/m K-32703-52
For US$240 + US$120 for a display

http://www.colepalmer.com

(800) 363-5900
page 718 of the 2007/2008 catalouge
I doubt you will get the 20:1 turndown you ask for in a cheap meter.
Regards
Roy

 

[roydm]

Page 733 of the 2010 on-line catalouge.
Roy