Low cost flow meter?
 

Just an idea all, how about I see about designing a low cost flow meter, we have all the parts in stock that we would need. You would just plug it in any fan port, that way will be 100% sure you always have flow.

Will just use CSP-MAG magnets, hall sensor, and jeweled bearings with low rpm paddle wheel. Given very low drag of bearings, it should be fairly accurate.

What you all think?

Any programmers around here that can make a cheap utility that shows flow based on RPM from meter, once I test the curves?

I think this would go a long way in helping find problems before CPU blows like on other thread?

A low-restriction low-cost flow meter monitored via the motherboard, scaled in the order of 1000RPM (at the mobo fan header) = 1LPM, would have many water-cooling enthusiasts chomping at the bit to buy one.

It is, I would warrant, the one device which many people express a desire for, for which there is yet to be an acceptable low-cost low-restriction solution for.

I have no idea how many people would buy one (as in how large the market is) but almost world-wide in various cooling forums I see perhaps 2 threads a week from people that ask for such a thing.

Just my 2c. I'd buy one in a heartbeat.

Me too! as long as it was reasonably priced and wasnt a restriction in a 1/2" setup

I'd definitely buy one too.



I've been looking for one for quite some time now; recently I found the DigiFlow 8000T. Isn't that a decent low cost flowmeter too? Not very accurate, but it doesn't look like a large restriction and it's not expensive. You can get one from Ebay here.
I'm sure you guys can do much better than that though. :)

This is a copy of my post in another thread, but...

Is it available yet? :)

How about instead of a paddle flow meter, use a spring-loaded lever that is pushed up against the side of the housing by the pressure of the water flowing by. This might create less restriction than a paddle, not to mention not requiring a bearing of any kind.

Just a thought. :)

$50-60 U.S and measures from .3 to 3.5 gpm - is that a high-enough range for your typical PC watercooling setup?

Yeah. I think most setups are between 0.5 and 2.5 GPM.
And that's $26, right? :p

I just checked it's specs again, and I think this won't work:
'Typical' pumps don't even get near 6 PSI.

Edit: nevermind... differential pressure doesn't get near 6 PSI. 1 bar ~15 PSI so it's fine I guess.

I would certainly be interested in a pair (mutiple loops going on here).

The best solution is to put dP sensors on the inlet and outlet of a radiator, measure the dP vs. Q curve for that radiator, and then do the conversion to flow rate in software. You would get good accuracy and NO restriction in the loop, and the parts aren't terribly expensive.

What's a dp sensor?

Differential Pressure sensor.

and how would you get the values from those sensors into the machine?
then get the calculated difference into software like MBM, WebTemp, LCDC?

I think you can use the RPM monitor on the mobo's fan header and read it through MBM. I don't really know at this point though.

don't think so...
you would need to take the data from the dP sensors... what kind of data that would be i don't know... and get it into the PC.... then do some calculations to get the flow rate...
i have RPM sensor on my pump so if the pump shuts off...
my machine will shut of...
of course if i have a leak... the pump will keep running...
my computer will drown and die... then shut off :evilaugh:

Dave:
I like the idea. What would be looking at for a price point? What about size? If you do it properly, I think you could reach 50-60% of the watercooling market (whatever that is). I think it would be great to have as a safety feature in a system. Pump failure isn't the only thing it would protect against. Think about a scenario in which part of the coolant system is external. If a leak were to form the system could potentially run out of fluid, frying the CPU.

I take it that is with AMD CPUs?
with P4's they just slow down...
atl least that is what i saw a while back on toms hardware
duno if that is still the case... anyone want to try?

I'll take one and we can talk about a review later.

Huh?
Dave is talking about making a low cost flow meter, something which tells you what the flow rate is; you're talking about making a dP vs Q curve for radiators when you somehow know exactly what Q, the flow rate, is.
Though of course I'd love to make a dP vs Q curve without spending too much money.

Offtopic, but I when I bought my Athlon 3400+ almost a year ago I accidently tested this: after 15 seconds or so the CPU got too hot and I was afraid I was going to have to buy another one.
I didn't have too, because it automatically shut itself down when it got too hot. Same for Intel CPU's since the Pentium 3 if I remember correctly. Internal temperature sensors. :)

granted it is off topic...
and my apologies for the continuation of the off topic discussion...
i beleive the thermal shut dow works great but it is proboly ment for stock systems...
how well will it handle an overclock system where the voltage is also pushed above specification?

back on topic...
how much will it affect the flow...
equivelt to a 90deg elbow? less? more?

I think something like this would be good, im almost sure I would get one. Just like this new setup im working on, I cant tell anything is moving without seeing the water swooshing around my res, esspecially with the MAG pumps being so quiet its really hard to tell. Would also be a nice compliment to the MAG if something like this looked similar too :cool:

Seems like most newer mobos feature an autoshutdown function regardless, but personally I dont like testing to see if its working :D

If what you really care about is running / not running maybe a pressure switch (no restriction), or if you knew the specifics of the system and could stand a slight restriction, then something that used bernoulli's principle to change the height of a column of water - and maybe something capacitive or optical to detect water column height.
Just a thought, of course...

i'd be interested. Any data acumulated and given to me by a sensor is always beneficial

Looking at it this way, all our instrument catalogs show paddle wheel type flow meter as least restrictive for this type of flow / pressure rates.

We use a paddle wheel type sensor at AVT and it costs thousands of dollars, for reasons I do not understand.

If you use a large wheel, and jeweled bearings with 1/2" passage, the loss of flow will be near zero.

Price should be cheap, I would say 10-15$ less then a MAG pump.
We would not need an AL case, stator assembly, nor volute chamber cut.
Would not even need a circuit board, our hall sensor can handle direct voltage.

If it becomes popular, will just use full injected plastic case, since it will be a simple 2 part mold.

Great you guys like the idea, because I do not want to go back to pump designer and ask him for more noise!

Will work on it this weekend.

But we still need a programmer, anyone know of someone that can help?

I'm a c++ programmer. What do you need?