Liq. Disp. 2

Archiver

Stampers,

Clarifications:

1) One liquid (Distilled water), 8 amounts

Suggestions by others:

2) Measure level w/ capacitance meter: How well does this actually work?

3) Pressurize the line and open 8 valves for different amounts of time (I'd
actually thought of this)

Question:

4) Where and what do I need for a pump?

5) Where and what do I need for valves

Thanks in advance,

David Fixemer

Archiver

I know for measuring Fuel levels using capacitance this is how all the large
aircraft do it. They use multiple capacitacnce meters, and run them thru a
signal conditioner, which totalizes tank fluid quantity. When I worked on
them as an aircraft mechanic they were always very reliable systems.

I dont know how well capacitance works in water however.


At 02:56 PM 1/31/2001 -0600, you wrote:
>Stampers,
>
>Clarifications:
>
>1) One liquid (Distilled water), 8 amounts
>
>Suggestions by others:
>
>2) Measure level w/ capacitance meter: How well does this actually work?
>
>3) Pressurize the line and open 8 valves for different amounts of time (I'd
>actually thought of this)
>
>Question:
>
>4) Where and what do I need for a pump?
>
>5) Where and what do I need for valves
>
>Thanks in advance,
>
>David Fixemer
>
>
>
>
>
>
>
>
>
Sincerely
Kerry
Admin@M...
WWW server hosting [url=Http://mntnweb.com]Http://mntnweb.com[/url]
Kerry Barlow
p.o. box 21
kirkwood ny
13795

Archiver

At 02:56 PM 1/31/2001 -0600, you wrote:
>Stampers,
>
>Clarifications:
>
>1) One liquid (Distilled water), 8 amounts
>
>Suggestions by others:
>
>2) Measure level w/ capacitance meter: How well does this actually work?
>
>3) Pressurize the line and open 8 valves for different amounts of time (I'd
>actually thought of this)
>
>Question:
>
>4) Where and what do I need for a pump?


What pump to pressurize the source? What is the volume per unit time?
For a 0.1ml per shot (200 mSec) system I developed, we used an aquarium
pump. We put a 3 psi regulator on it and fed it into an accumulator (tank)
and this was our pressure source. If it is large enough, your can manifold
off of it and won't see any pressure difference wether you have one valve
open or eight.


>5) Where and what do I need for valves

I have used Clippard http://www.clippard.com for the last few projects.
They are affordable, provide easy to use documentation for their products
and have a local distributor for me. I see they sell directly, on line, now.



>Thanks in advance,
>
>David Fixemer

_________________________________
Mike Walsh
walsh@i...

Archiver

Hi David,

Here is one of the links to the tank thread.
http://groups.yahoo.com/group/basicstamps/message/5451

It should give you some data on the capacitance method.

There should be some help on this list on that sensor style, or even
contact Ebow and see how he worked out his problem, and let him know
we're still thinking about him and would be interested in finding out
how it worked.


Regarding valves, you can get solenoid valves from many places. if
you need stainless or brass or chrome plated, you can find them in
Granger, McMAster Carr, or manufacturers like Clippard. The larger
the valve opening, the faster the flow. the smaller, the longer time
to fill/drain, but for filling, you may get better accuracy with a
smaller valve.

A brass solenoid 1/8" inch pipe connection, 24 VDC from Clippard is
about $25. one to fill and one to drain, some relays and wiring and
you're in around $100.00 The brass will have a stainless or chrome
stem, rubber O-rings, and some type of silicone sealant, so look for
contaminants from any of those sources.

With pumps, you have the same consideration. How pure is your fluid,
and how much contaminants will the pump put into your system? USCO
has some pumps, but it's easy to blow the big bucks on high sterility
pumps.

Another potential is to use gravity again. You get the DI from
somewhere? can it be pressurized? or can the discharge be in a
container on a shelf?

One possible solution is to take a gallon (5 gallon) glass container
like a water cooler bottle, and pressurize it with a few PSI. One
PSI will raise water 27 inches, so 3 PSI will raise almost 7 feet off
the floor. A rubber stopper with two holes will let you fill,
pressurize and even offer a relief valve.

If you're creative and you have compressed air, you can get away
without pumps. Just Gravity and air pressure.

If you have compressed air, you can even use pinch valves on the
tubing with small pnuematic actuators and small solenoids to control
the air.

You didn't mention quantity. Are you filling gallons? or cups?
Larger valves will cost more but work faster. pinch valves may be
cost effective as the cost is low, but tubing can be big.








--- In basicstamps@y..., MIKE WALSH <walsh@c...> wrote:
> At 02:56 PM 1/31/2001 -0600, you wrote:
> >Stampers,
> >
> >Clarifications:
> >
> >1) One liquid (Distilled water), 8 amounts
> >
> >Suggestions by others:
> >
> >2) Measure level w/ capacitance meter: How well does this
actually work?
> >
> >3) Pressurize the line and open 8 valves for different amounts of
time (I'd
> >actually thought of this)
> >
> >Question:
> >
> >4) Where and what do I need for a pump?
>
>
> What pump to pressurize the source? What is the volume per unit
time?
> For a 0.1ml per shot (200 mSec) system I developed, we used an
aquarium
> pump. We put a 3 psi regulator on it and fed it into an accumulator
(tank)
> and this was our pressure source. If it is large enough, your can
manifold
> off of it and won't see any pressure difference wether you have one
valve
> open or eight.
>
>
> >5) Where and what do I need for valves
>
> I have used Clippard http://www.clippard.com for the last few
projects.
> They are affordable, provide easy to use documentation for their
products
> and have a local distributor for me. I see they sell directly, on
line, now.
>
>
>
> >Thanks in advance,
> >
> >David Fixemer
>
> _________________________________
> Mike Walsh
> walsh@i...