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Mass/Flow Meter? 1

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RayRogers

Electrical
Joined
Dec 19, 2001
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9
Location
US
I have a need for a flow meter that can measure water: 3nL/pulse, 1 pulse per second, so that the accumulated accuracy for 30nl is better than .3 nL.
Any suggestions? We are trying weighing with a pecision scale but the water keeps evaporating. I can control the evaporation, but would prefer to buy an off the shelf instruments.

Ray
 
Maybe a Thermal Liquid flow meter? (standard smallest range 0-12.5 mg/hr normally) You can ask manufacurers how low they can go. The smallest corioles meters go down to 50 g/hr, but there are rumours smaller ranges are on the way.
 
hi Sierra

what about magnetic flow meters
only if we have coductive fluid

adil4adil
 
We have solved the problem. It turns out that there is a
market in Pipetters for medical research putposes. These
managed to satisfy our needs.
 
Ray,

What is the brand of the unit that finally worked for you?

Rocco8
 
Ray, you might look at the small excellent meter from Belgium, avaialable in the USA at:
excerpt:
The DFS-2W has a linear flow range of 0.07– 4.5 l/m (.02–1.2GPM), turndown of 64:1, resolution of 60,000 pulses/liter (227,100/Gal.) Process connection is 7mm ( 9 /32 ") hose barb fitting.
Cheers!
Tom Ramey
 
tomramey,
Thanks, but the resolution doesn't seem adequate. The design reminds me of an idea I had to make a 0 pressure drop flow meter using a higher order control loop to drive a pump just so that the pressure drop around the pump was zero. I envisioned a smooth spiral type of rotor.
Never did anything with it though. Just an idea when we wanted to experimental monitor flow without disturbing the flow.


Thanks again
Ray
 
Ray --
not a bad idea, doesn't sound to energy-efficient though, lasers, optical, magnetic, all the non-contact technologies are comig along steadily, in terms of non-invasive flow measurement. Last thing the world needs is another flowmeter, also, there are thousands of designs and embodiments. Anyway, enjoy the Veteran's Day holiday, I'm doing some landscaping/gardening myself, just checking in on email every hour or two to keep the empire rolling. Ciao!
 
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