Post by thread:[PIC]: Need a flow sensor

Hello everyone, I´m involved in a project in wich have to measeure how many liters of diesel flowed to a motor (diesel consumption) in a a predefined lapse of time. Measure will be made with a PIC micro, and so will the time. Now, does anyone know of a good and cheap turbine flow sensor I could use for this project ? Thanks in advance, Gabriel.- -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

>When measuring consumption keep in mind that most diesels have a return pipe. The idle flow through the system is much higher than the consumption in my experience. So you will have to measure delta (inflow-outflow) very accurately. You MAY be able to take a small "T" feed off the go & return system into the injection system so only the delta flows in the leg of the T. If not then the result (the actual flow calculated by subtracting return from feed) may be "ill conditioned". eg if feed is 100 units and return is 98 units then a 1% error in measurement produces a 50% variation in final result. RM -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

Every time I've asked about this sort of application every seems to say "Measure the injection pulses for one injector", and indicate that flow sensors meant to measure such a small flow are very expensive, and injectors are very accurately timed. Of course, if this isn't an injected engine then this doesn't apply. -Adam Gabriel Caffese wrote: {Quote hidden}>Hello everyone, > > I4m involved in a project in wich have to measeure how >many liters of diesel flowed to a motor (diesel consumption) >in a a predefined lapse of time. > Measure will be made with a PIC micro, and so will the time. > Now, does anyone know of a good and cheap turbine flow sensor >I could use for this project ? > > Thanks in advance, > > Gabriel.- > >-- >http://www.piclist.com hint: The PICList is archived three different >ways. See http://www.piclist.com/#archives for details. > > > > > -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

> > I4m involved in a project in wich have to measeure how >many liters of diesel flowed to a motor (diesel consumption) >in a a predefined lapse of time. > Measure will be made with a PIC micro, and so will the time. > Now, does anyone know of a good and cheap turbine flow sensor >I could use for this project ? If the injection system is electric, you can probably sense "squirts" and convert that to gallons. Zemco car computers for fuel injection used to work that way. -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

The most reliable way I've ever seem is the method used to measure liquids for certain blood handling systems. The liquid is in a flexible hose, which is mounted on the outside of a wheel. Two roller cams press against the hose simultaneously, rolling as they move. The liquid between the cams is trapped and pumped along at the same time. Another roller cam catches as the forward one drops off. Just keep count of the squirts by sensing when a roller cam passes by. The main advantage of this scheme is that it works at almost all flow rates; most flow meters have a minimum reliable flow rate. And, gravity (or momentum) has no effect. --Bob David VanHorn wrote: {Quote hidden}>> I4m involved in a project in wich have to measeure how >>many liters of diesel flowed to a motor (diesel consumption) >>in a a predefined lapse of time. >> Measure will be made with a PIC micro, and so will the time. >> Now, does anyone know of a good and cheap turbine flow sensor >>I could use for this project ? > > > If the injection system is electric, you can probably sense "squirts" and convert that to gallons. Zemco car computers for fuel injection used to work that way. > > -- > http://www.piclist.com hint: The PICList is archived three different > ways. See http://www.piclist.com/#archives for details. > -- Replies: NOTE-Script, EXE,BAT and COM files will be rejected by server -------------- Bob Axtell PIC Hardware & Firmware Dev http://beam.to/baxtell 1-520-219-2363 -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email spam_OUTlistservTakeThisOuTmitvma.mit.edu with SET PICList DIGEST in the body

Yeah, it's called a peristaltic pump. Shawn Wilton Junior in CpE MicroBiologist Phone: (503) 881-2707 Email: .....shawnKILLspam@spam@black9.net http://black9.net Bob Axtell wrote: {Quote hidden}> The most reliable way I've ever seem is the method used to measure > liquids for certain blood handling systems. > > The liquid is in a flexible hose, which is mounted on the outside of a > wheel. Two roller cams press against the hose simultaneously, rolling as > they move. The liquid between the cams is trapped and pumped along at > the same time. Another roller cam catches as the forward one drops off. > Just keep count of the squirts by sensing when a roller cam passes by. > > The main advantage of this scheme is that it works at almost all flow > rates; most flow meters have a minimum reliable flow rate. > > And, gravity (or momentum) has no effect. > > > --Bob > > > David VanHorn wrote: > >>> I4m involved in a project in wich have to measeure how >>> many liters of diesel flowed to a motor (diesel consumption) >>> in a a predefined lapse of time. >>> Measure will be made with a PIC micro, and so will the time. >>> Now, does anyone know of a good and cheap turbine flow sensor >>> I could use for this project ? >> >> >> >> If the injection system is electric, you can probably sense "squirts" >> and convert that to gallons. Zemco car computers for fuel injection >> used to work that way. >> >> -- >> http://www.piclist.com hint: The PICList is archived three different >> ways. See http://www.piclist.com/#archives for details. >> > > > -- > > Replies: NOTE-Script, EXE,BAT and COM > files will be rejected by server > -------------- > Bob Axtell > PIC Hardware & Firmware Dev > http://beam.to/baxtell > 1-520-219-2363 > > -- > http://www.piclist.com#nomail Going offline? Don't AutoReply us! > email listservKILLspammitvma.mit.edu with SET PICList DIGEST in the body -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email .....listservKILLspam.....mitvma.mit.edu with SET PICList DIGEST in the body

I believe most new cars that have an onboard MPG meter use a combination of the fuel guage, the mass airflow sensor (at least on gasonline engines) and maybe even the injector pulses/RPM to calculate MPG. On my last VW Jetta/Bora, the MPG reported by the car used to be close enough (always within 10%) of the actual MPG. After I replaced a dead MAF sensor on it, the reported MPG was way off and I had to adjust it using the programming of the instrument cluster. But I don't think it had a liquid flow sensor anywhere on the fuel lines. At least I never saw one in the repair manuals or on the car itself. A friend of mine working on a similar project in school (long time ago) used a small staging tank and sensors to see how quickly the tank was depleted. Once the tank was almost empty, a small pump would refill it from the main tank. I have seen fuel consumption kits for boat engines at marine stores which have a fuel flow sensor with them. But if I recall correctly, the box for the kit said not for engines with return fuel lines. Shahid {Original Message removed}

Hi If you want to make your own, you could make a drip counter. a small cavity with a nozzle, and a light interrupter to count the drops. It'll have to stay upright and be buffered with an air-pocket to prevent squirts. Not sure how temp changes in the diesel will affect drop size. Of course, we're only talking about the fuel to be used that'll be measured. Regards Roland -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email EraseMElistservspam_OUTTakeThisOuTmitvma.mit.edu with SET PICList DIGEST in the body

part 1 977 bytes content-type:text/plain; charset=iso-8859-1 (decoded quoted-printable) Floscan 201. Very easy to interface, but not cheap. Most cars nowadays measure fuel consumption by counting the time the fuel injectors are open. Regards, Bob Gabriel Caffese <gcaffesespam_OUTHOTPOP.COM> wrote .. {Quote hidden}> Hello everyone, > > I�m involved in a project in wich have to measeure how > many liters of diesel flowed to a motor (diesel consumption) > in a a predefined lapse of time. > Measure will be made with a PIC micro, and so will the time. > Now, does anyone know of a good and cheap turbine flow sensor > I could use for this project ? > > Thanks in advance, > > Gabriel.- > > -- > http://www.piclist.com hint: The PICList is archived three different > ways. See http://www.piclist.com/#archives for details. -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email @spam@listservKILLspammitvma.mit.edu with SET PICList DIGEST in the body