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Cies Fuel Sender System

Selmax

Member
CIES Inc., Oregon, has a patented technology (Patent 6,508,119) for providing fuel level indication in analog and digital applications using a unique sensor system. As built in Cirrus Perspective since years they might have an excellent reputation concerning accuracy of fuel level indication.

http://ciescorp.com/CIES_In_1./Fuel_Sender.html

Any experience with CIES fuel senders in a Vans already? :cool:

Pit
 
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I spoke with Cies today. They said that that press release was premature and that they do not have a product for any RV.

However, he asked me to send him photos and drawings of the tanks and that he would look into the possibility of using/modifying one of thier existing senders for me.

This issue has been a concern to me. Vans is adamantly against CapSends in my 10 and builders are strongly against vans floats. I wish/hope for a better option...SOON!
 
The arguments against were...

1) More expensive
2) Much more difficult to repair
3) Impossible to clean/maintain

I was planning on using CapSends as it seems most builders have made that choice. I was advised by Van's to check into how many of these systems are actually flying as opposed to being built. The Cies system seems to cure 2 or 3 of those problems while providing MORE accuracy. There are woefully few options for the RV when it comes to fuel senders. I'm hoping this changes.
 
Sorry to have been silent - We are working the RV project semi-actively. We carefully did the mechanical design as seen on the blogpost we did www.fuellevel.blogspot.com. Our first thought was to use the circuit card from the TSO sender with the digital frequency for the Garmin G1000/G2000 system. - First no other MFD accepts that signal except Garmin and JPI on the 930, Second - it was going to be priced as much as a certified unit

So we are finalizing a sender circuit card for a much larger market - this circuit card uses all the technology we developed for the Cirrus Aircraft but multiple outputs are supported and it is not FAA approved.

Resistance, Voltage, Frequency and RS-486 are supported - so no compatibility issues with any gauge

We need to test fit an aircraft and establish a pricing structure for the RV market -

You can help
 
I'm not sure this solves the main issue with fuel senders. On my RV-8 with normal float type senders

1) anything above 15 gallons is something between 16 and 20 gallons
2) anything below 4 or 5 gallons is something between 0 and 5 gallons
3) with the Vans gauges anything between 5 and 15 is, well, something between 5 and 15 gallons but I could never be really sure.

SkyView gives pretty accurate readings between 5 and 15 but the limitations of the senders make 0-5 and 15-20 dead zones. The Cies sender may make things less sensitive to ripples, waves, accelerations, banks and pitch but most of that is damped out in SkyView and other modern systems anyway.

Am I missing something or is this a solution in search of a problem?
 
The only analogy to draw here, as there are no RV Pireps, is that current production or retrofitted Cirrus SR20 or SR22 have these installed -

In these aircraft - fuel level became newsworthy .

Flying
Plane and Pilot
Aviation Consumer

The solution did find a problem with Cirrus and other OEM's and an appreciating audience.

By any and all standards we don't have issues like 1,2 or 3 -

What we report is an accurate fuel level remaining and it matches a computed fuel level remaining from an accurate fuel flow transducer and instrument. If there is a discrepancy fuel level to fuel remaining - you are losing fuel (Vented, Bad Cap, Fuel pump leak)

I am running a performance tests to solve an interesting multi tank fuel level issue - My stick gauge is repeatedly measuring the same displayed fuel value - during vibration I get a peak to peak average -

If the senders in your aircraft have a dead zone that is not a characteristic of all senders nor is it a universal to all senders regardless of how they derive the fluid level.

Our senders have floats but our measurement method is entirely different to any float sender you have held - This is not your average float sender. Watch the attached video and you will see what we are talking about. Using this technology is a CiES patent for fluid measurement

http://youtu.be/ww3IsROsbwc?t=1m20s

Send a Van's member by - we'd love to show what we can do
 
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As we have made quite a bit of progress on other fuel level sending markets, that now allows us to offer a non-FAA certified circuitry for the RV fuel sender. The circuitry component is designed for harsh automotive / truck / heavy equipment environment and will be fine for aviation. The remainder of the sender, the physical portion, maintains our aviation component standard.

http://http://www.ciescorp.net/vans-rv-fuel-level.html

Let us know and we will kick the program into gear
 
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You had me at "hello". I've been flying my -4 with the senders supplied by Van's for 13 years. As far as I am concerned, they serve only to keep the fuel from draining out the holes I cut in the tank to mount them. Some years ago, I mated them with an EI gauge that allowed me to program out the non-linear nature of the floats, but the results were still not satisfying. For years, I have been relying on my EI fuel totalizer to manage my fuel status. A couple of questions:

Is the interface (bolt pattern) the same as the SW senders that came with my kit?
Can I use my existing EI gauge, or will I need a new one?
When will the system be available?
How much will it cost?

Regards,
 
The mechanical interface is identical to the Stewart Warner System
You can use the existing EI gauge
We plan on offering this in the first quarter of 2015 - pending interest
$148 per sender.

I'd like to outfit a few trial aircraft to insure compatibility - you never know with aircraft
 
We moved last month - we needed more office space and as all of us were commuting from Bend - we made the move - If you are local, please visit. Post a visit report
 
last 5 gallons?

When the first inboard bay of the fuel tank is just about full, the tank is still missing about 5 gallons of fuel in an RV-10.
The problem isn't that the SW senders are inaccurate. When calibrated properly they work well. You just can't measure the top 5 gallons.
I'll happily pay the $150/sender as long as you can measure all the fuel in the tank with them.
According to some rough volume calculations, even if you can measure up to the top of the second bay you're still only getting 28 gallons out of 30.

Lenny
 
Lenny: Yes I heard this before - our float is smaller as our float doesn't have to move a pointer across a potentiometer - it just needs to float @ midpoint bouyancy.

The other issue we saw is that the float on the SW component hits structure and not the top of the skin. Several people have modified the float to fix this issue. Is that the reason for the 5 gallon discrepancy? Wilmar & CiES seem to think that this may be part of the reason.

We live fuel level in certified aircraft this is our full time job and not an adjunct to something else. We did a lot to position the float in the right place and to limit anything to catch on structure. We do this with proven consistantly for OEM installations.

What I don't understand is how a capacitive sender 2 inches further outboard from posted dialogue appears to be able to measure full fuel volume in the RV. It doesn't make physical sense, from what I know.

However I am always willing to learn something new. We have a test rack and we can set dihedral and simulate flow.

Our senders are configured to be master / slave - you can always deviate from the plan and add an outbd sender.
 
The 5 gallon issues is there because of the wing dihedral.

fueltank.jpg


You cannot measure any fuel that's in the red area, unless you add an outboard float.

Capacitive fuel senders are built in when building the tank and they span the whole length of the tank (capacitive tubes), or by using capacitive plates on the inboard and outboard ends of the tank.
Neither is easily doable with quickbuild tanks though.
I tried to see if I can fit a capacitive sender up to the top of the second inboard tank bay, but it just cannot be done with the wings on the plane. There's not enough room at the wingroot.

I was thinking to measure the fuel level using a differential pressure sensor, measuring hydrostatic pressure, but it gets way too complicated.

Lenny
 
Lenny:

Well that saves a lot of time and energy.

I would say that two senders per tank are required to measure full fuel - is there access to the outbd tank rib to make this feasible alternative on the wing. Our system is set up for this contingency as many OEM systems require two senders.

One of our main benefits as we are unaffected by temp / vibe which makes the system pretty bulletproof fuel level measurement wise. We had investigated a lot of alternative technology or improving current systems like capacitive. We are finding we have a better solution for fuel level measurement and replacing all types in the certified field

I updated the Van's page to show a comparative to the Stewart Warner sender
 
How much do you need to know?

I'm interested in these senders as well; I have tanks under construction now with the baffle still to be installed. I've dropped a note on the Cies site saying I'm interested, but just how accurately do you need to know the level of the top of the tank? If my system read "full" anytime it had more than 3/4 of it's capacity, and then accurately reported the level as it went to empty, that sounds pretty useful to me. Many replies here have said that once you fill the tanks and update the EFIS, then the fuel flow keeps the EFIS level accurate, and the float gauges are there as confirmation when you're getting towards the end. I have no doubt "better is possible" (to coin a phrase), and I'm interested in "better", but I'm not sure "better" is really more useful.
 
Clay: Yes there are several thoughts about fuel level in the aviation community.:

In those aircraft that we are installed that can read full fuel. Owners use an accurate fuel gauge to confirm or establish partial fuel loading for the aircraft. Owners also use it to compare the the line receipt or added gallons to confirm actual fuel loading on the aircraft. It answers the question "Did the line guy get my fuel instruction right"

Some pilots believe there is no other starting fuel level - other than full.

Confirmation of fuel remaining indicated in the tank and by the EFIS is comforting.

I know this is heresy, so don't shoot the messenger - We are aware of pilots of Cirrus aircraft that defer to the gauge over the fuel totalizer in the MFD. These pilots make decisions based on the actual fuel onboard vs a calculation based on an initial fuel level estimate decremented by a flowmeter measuring fuel flow.

The Cirrus actually warns about fuel imbalance based on fuel tank values - this is only good if you can measure full fuel volume.


In the case of the Van's aircraft illustrated very well by Lenny I - "Better" may be available but it would take another pair of senders to get there.
 
new CIES fuel senders in a RV 9a

presently my fuel indication is awful but I am glad I have the G3X fuel page

The mechanical interface is identical to the
Stewart Warner System
We plan on offering this in the first quarter of 2015 - pending interest
$148 per sender.


Is there any experience with these new CIES fuel senders in a RV 9a already out there? :cool:

thanks Pit
 
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Is there any experience with these new CIES fuel senders in a RV 9a already out there? :cool:

I talked to them at Oshkosh and saw the system in a demo they had set up.
It seems it's not out yet, but they do have a couple people testing them in real aircraft. If I understood correctly one could buy the certified system and use it in an RV, but that'd be something like US$300 per sensor, and they're working on making a cheaper non-certified version.

The install will be non-trivial, simply because they use *two* senders, one on each end of the tank, to measure the full range (so dihedral is no longer a factor) - meaning another hole on the other side, possible opening up the tank to install nutplates, etc.

That said, I liked the "solid" look of the system - the inside (that goes into the tank) looks like a solid metal block with no moving parts other than the arm.
 
I use the system in an -10. I have two senders each tank (inboard/outboard). Very accurate, no fluctuation, coupled to G3x.
 
I was probably the first RV-10. We recorded the fuel measurement for Scotts chip. Measured voltage every two gallons, then flashed chip, then reinstalled. Scott now has the information to provide hardware for any -10 (vans has a different sender for each side rather than the same sender for both sides). There is something called a "Cessna fuel nut ring" that works great for Vans/Scott's senders (you don't use the individual nut plates, rather the nut ring - solid one piece ring that seals easier).

Hope this helps.
 
I was probably the first RV-10. We recorded the fuel measurement for Scotts chip. Measured voltage every two gallons, then flashed chip, then reinstalled. Scott now has the information to provide hardware for any -10 (vans has a different sender for each side rather than the same sender for both sides). There is something called a "Cessna fuel nut ring" that works great for Vans/Scott's senders (you don't use the individual nut plates, rather the nut ring - solid one piece ring that seals easier).

Hope this helps.

Interesting. To insert that nut ring you still had to open up the tank, right? Or was it an easy retrofit somehow?
 
Retrofit

Yes - we installed an inspection hole in back of tank to install ring.

Thats a big deal for a retrofit, isn't it? Do you know if Cies would provide a single sender for each tank. I can live with accuracy when the fuel is nearing the lower levels.

Thanks Pit
 
You can use the Cies system with one sender per tank. This would still be superior to any stock sender hands down. I would absolutely prefer and recommend one Cies sender over stock Vans units.
 
Evolution

Thanks Evolution10,
Good advice, thanks. Do you know whom to contact at CIES and who is probably familiar with the set up in a RV9 with a G3X?
Pit
 
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I tried twice to get in contact with CIES, unfortunately no answer ...

I managed to talk to them by phone just before OSH, then met them there, but what they said was basically that they're still working on it (what they have now - or had then - is certified and costs almost $200/sensor - $800 total). You can try calling them.
 
I am around - we have been buried with OEM work lately. The Vans aircraft presents some difficulties. One - the Van's aircraft sender location only measures partial fuel volume unless you go to the effort Evolution 10 went to to add outbd senders - this is the preferred solution as it meets the regulations for indicating usable fuel to the pilot. Two - if you only use 1 sensor per tank which will not measure all usable fuel the clearance to structure is critical and would suggest a new float to insure clearance is maintained - that would be a custom mold and float. I took the concerns to Van's (over the mountains) and they were not interested.

Three - we have been an aircraft manufacturer only to date and that leaves us with a very robust and very expensive TSO'd circuit card. We have a commercial grade card in prototype phase but we need a market (Marine, Propane Truck, Gen-set) to make this a viable option at the price point I have indicated in the sign up sheet. We have interested parties - but no one has taken the bait.

The issue we face that while we are new technology to measure fuel - we look like the legacy system that has experienced failure and poor reporting. People expect new technology to look new - ours just doesn't. Its simple and retrofittable - all good points. So any claims that I can back up with hard data fall on deaf ears - 16,000 senders, 375,000 operational hours No Unscheduled removals - best in class accuracy exceeding any other fuel measurement technology only to be met with questions on how to we insure the float will float and the final condemnation of floats don't work - (NBR Closed Cell Foam if you want to know)

The G3X will take a frequency input - I checked and we have a Bonanza in EXP flying with that interface
 
Float

I am around -
Two - if you only use 1 sensor per tank which will not measure all usable fuel the clearance to structure is critical and would suggest a new float to insure clearance is maintained - that would be a custom mold and

The G3X will take a frequency input - I checked and we have a Bonanza in EXP flying with that interface

Thanks Fuellevel. Do I have to fabricate my own float if I am going with a CIES fuelsender for the RV9? Did I got your message right?
 
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Found this thread after seeing the CiES booth at Oshkosh this year and reading the article about them in the Aug issue of Sport Aviation. Sure hope they decide to produce the fuel sender for RVs.

On my RV-8A I used the Princeton capacitive senders and they worked pretty well, although a few times had issues that were probably related to a drop of water or other contamination affecting the capacitance between the inner and outer elements. At least they were solid state with no moving parts and I never had to remove/replace them. However the pre-bent Princeton probes don't fit the RV-14 tanks, and I am also uncertain how the various fuels that will replace 100LL will affect capacitance probe accuracy. So I reluctantly installed the Stewart Warner senders included with the kit but would really like something better.

If anyone else wants to encourage CiES to produce a probe specific to the RV series it looks like their website still has a page where you can do that:

https://www.ciescorp.net/vans-rv-fuel-level.html
 
CiES fuel sending units for RV

I would like to weigh in on the CiES fuel sending unit product. I have spen a great deal on time on a fuel sending unit prounrelated to the RV application but similar. In the process I have spent some time discussing their technology with them and have more than passing understanding of the technologies they are using.

In my opinion they probably have as good an understanding of the issues related to fuel level sensing and display in aircraft than anyone out there. They have a first rate solution and if I were building an RV today or any other aircraft with wing dihedral, I would seriously consider putting two of their sensors in each tank. I believe that there is probably not a electrical fuel level instrument/display out there that they cannot interface to.

If they can indeed deliver fuel sending units to non TSO installations for $148 per sensor I would consider that a deal. Not a $12 Delco wirewound resistor constantly bathed in fuel. Eyeballs in the tank, timing legs, and monitoring fuel flow will always be the gold standard but if you want to reduce the uncertainty of what is displayed on your $6k to $30k panel take a look.

https://www.ciescorp.net/vans-rv-fuel-level.html

I don't have any interest in CiES beyond a technical interest in the technology they are using and believing that they have a good product and an interest in making aviation a bit safer for all of us.

-Larosta
 
It seems odd to me that they would work so hard to solve the dihedral problem where the inboard sensor shows the tank is at 16 gallons for any fuel level between 16 gallons and full (21 gallons).

WHO CARES! If my gauge reads 16 gallons, I know that I have somewhere between 16 and 21 gallons. The fuel flow/fuel totalizer will tell me what the level is.

Look, what you want is a robust (meaning accurate and reliable) fuel level indication when the tank is between half full and empty, so that you have a second, redundant indication in addition to the fuel flow/fuel totalizer. If they EVER disagree, you should seek to find out why. Leaky fuel drain, missing fuel cap, fuel going somewhere it is not supposed to go, whatever. That is why you want the gauge. If the gauge shows 16 gallons, you know you are safe.

So, what we should care about is that the gauge is accurate when it matters. And the CiES sensors seem to deliver that. Great. I want them. But to add a second sensor at the outboard end of the tank to solve a non-problem just introduces the potential for other problems.
 
It seems odd to me that they would work so hard to solve the dihedral problem where the inboard sensor shows the tank is at 16 gallons for any fuel level between 16 gallons and full (21 gallons).

WHO CARES! If my gauge reads 16 gallons, I know that I have somewhere between 16 and 21 gallons. The fuel flow/fuel totalizer will tell me what the level is.

Look, what you want is a robust (meaning accurate and reliable) fuel level indication when the tank is between half full and empty, so that you have a second, redundant indication in addition to the fuel flow/fuel totalizer. If they EVER disagree, you should seek to find out why. Leaky fuel drain, missing fuel cap, fuel going somewhere it is not supposed to go, whatever. That is why you want the gauge. If the gauge shows 16 gallons, you know you are safe.

So, what we should care about is that the gauge is accurate when it matters. And the CiES sensors seem to deliver that. Great. I want them. But to add a second sensor at the outboard end of the tank to solve a non-problem just introduces the potential for other problems.

Personally I am only interested in a more reliable sensor at the inboard standard fuel sender location. Agree it seems like overkill in an RV to add a second sender at the outboard end of the tank. I hope that isn't what is keeping CiES from getting the probe to market for RVs. Let us buy the inboard unit and if they really think there's enough demand to build an outboard unit for RV tanks then do that as a follow-on product...
 
Personally I am only interested in a more reliable sensor at the inboard standard fuel sender location. Agree it seems like overkill in an RV to add a second sender at the outboard end of the tank. I hope that isn't what is keeping CiES from getting the probe to market for RVs. Let us buy the inboard unit and if they really think there's enough demand to build an outboard unit for RV tanks then do that as a follow-on product...

Agreed! I would buy a pair today at $150 each.
 
Waiting ...

I filled out the form, it only took two minutes, hope something comes of this.

Thats exactly what I did .... two years ago ... no answer! And I would buy two sets ... in the meantime, my neighbour has just finished his RV9a. He needs them urgently ... before mounting the wings :cool:
 
Mark, I just stumbled across this thread after posting my opinion poll on this very topic. I had never heard of them before.

I believe that it is hard to beat the capacitance senders that unfortunately van no longer sells.

To make your own would not be very hard at all.

Personally I don't know why anyone would go any other route unless your project were a quick build kit.

My two...

:rolleyes: CJ
 
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