Flow Sensor

[Jerome Ebel]

I'm looking for a flow sensor similar to the one described in the March '03 issue of Nuts & Volts, Water Flow Meter and Event Timer. The one in the article is not available in the US. Does anyone know where I might find one?

[bodgy]

The one in the article is available from RS Components who will export. They do have two subsideries in the US, I think (but not sure )one may be Newark and the other has another name.<p>However RS postal charges aren't cheap, but it may be worth looking at the UK site where export to the US are dispatched.<p>There are other places that sell flow sensors -Rapid in the UK,Matrix Multimedia,Willow Sensors (UK), I'm sure there are equivalents in the US.<p>Naturally the others probably require a different calibration figure.<p>If you are able to find an alternative supplier, and it has a different calibration number, I could send you a hex file with that number compiled. However it must be a flow sensor that emits pulses per Ltr/Gallon.<p>It might also be worth doing a google search for V8189, this maybe the sensors manufacturer number. Unfortunately the sensor is an RS badged product so the OEM is a bit difficult to find.<p>My brain just clicked into gear! Also look at flow sensors for car computers, the type that go in the fuel line. Many of those give off pulses per quantity - so maybe a breakers yard or an auto spare parts place may be a place to look. So long as the output pulse is TTL and it preferably can run off 5v, the only probelm then is finding the calibration figure, which is just how many revolutions per quantity it does.<p>Colin<p>[ September 22, 2003: Message edited by: bodgy ]</p>

[Jerome Ebel]

I talked to a rep from Allied, which is the state side dealer for RS components and they do not carry that product. Neither could I find it on the Rapid site. I can get it thru Allied for ~$40 but I have to order a minimum of 5. To much for me! I found it on the UK site but was unsure of monetary conversion rates or postage rates. I would surely like to simplify this purchase and know up front my cost. BTW, I'm not building that project but rather an automated homebrewing (beer) project. I will try the Google search and Newark and keep my fingers crossed that someone on this forum has more specific info.
Because I like to drink my beer I don't think that a used fuel flow sensor will work!!
Thanks<p>[ September 22, 2003: Message edited by: Jerome Ebel ]</p>

[bodgy]

And what is wrong with 100 octane flavoured beer? that is what I want to know.<p>The one from Rapid is not exactly the same, just similar. Now theirs is from a company called Gems Sensors, who I think I've seen on the web.<p>The part #'s from Rapid are <p>61-1550 0.5-5Lt.min
61-1552 1-10L/min
61-1554 1-15L/min
61-1558 2-30L/min<p>all at £31.00. However Rapid unfortunately have a minimum foreign order of £75.00, well to australia they do anyhow.<p>For RS you have to email them and they will tell you the cost, I don't think from the parent company the min MSU is 5, but I haven't looked at the UK site as I say that.<p>Perhaps medical equipment manufacturers might be the way to go. I did find some other US manufacturers that do what you are looking for who well sell over the Internet, but they seemed horrendously expensive - between U$90-150.00.<p>Not sure if a brand new car intended flow sensor would use food safe plastic/SSteel or bearings.<p>You could at a pinch try my suggestion in the text, all you need is either an infra red LED or magnet and opposite it aeither an infra red detector or hall effect sensor, an amplifier for the signal plus a schmidt trigger if you want TTL output.<p>Then some kind of vane or paddle wheel to interrupt the beam. The parts I doubt would be no more than U$15 - U$20, just the fiddly bit of building and adjusting.<p>Now where is my Kerosene flavoured lager?<p>Colin<p>PS I could get you one from RS here, they are about A$45.00 but I shudder to think of the postage cost.<p>PPS. For exchange rates http://www.xe.com/ucc/<p>[ September 22, 2003: Message edited by: bodgy ]<p>[ September 22, 2003: Message edited by: bodgy ]</p>

[Jerome Ebel]

I found one thru Newark for ~&75 and it is a Gem Sensor model. This is within my range. Thanks alot for the help. If you were a little closer I'd invite you over for a cold one. I can assure you that the octane level is more than sufficient! The brewery that I used to run won a World Cup Beer award for our barley wine which came in at over 11.5% ABV.

[Will]

If you are happy with your sensor and the cost of it that's OK - A very simple way to measure flow is to take a glass tube, cover one end with a piece of thin plate,( copper or whatever takes your fancy) with a small hole in the middle. (Use araldite or some suitable glue to stick the plate) now mount the tube vertical with the blocked end at the bottom and pour your liquid into the tube. Once the height of the liquid in the tube stabilizes at some value (Height above botton of tube) then that height is a measure of the flow rate. I could tell you the size of the hole if you told me the range of flow values you need to measure but in any event, because of variations in the CoEfficient of Discharge, you would need to calibrate it. That would be fairly simple to do, simply get the flow going at some steady rate and then time how long it takes to fill a calibrated volume. Such a calibrated volume would be easy to arrange. Just weigh an empty beer bottle or something similar and then fill it with water and weigh it again. The difference in weights is the mass of the water and, if the mass is (W) in pounds then the volume (In cubic inches) is W/62.376 * 1728.
You can then mark the side of the glass tube with square root scale marked in Cubic Inches/min or whatever