Specific Gravity Fuel Tester

[stevenclin]

A long time ago - maybe 10-15 years - Sporty's used to sell a fuel tester cup that had a small yellow ball in it. The ball had the appropriate density to sink in avgas but float in Jet A (and water). So, if the ball was floating or partially floating, you knew you might have some contaminant in your tanks, but if it sunk, you knew you likely had avgas.

I was looking to buy such a fuel tester and discovered that they don't seem to sell this type of thing anymore. Neither does Aircraft Spruce or Sky Geek or my other usual sources.

Has anyone seen this type of tester in the recent past and/or know of a source?

Thanks!
Steve

 

[MAKG1]

There are MUCH easier ways to detect jet fuel.

Easiest is to drop it on some white paper. AvGas evaporates right away. Jet fuel is greasy and won't.

 

[Brad Z]

There are MUCH easier ways to detect jet fuel.

Easiest is to drop it on some white paper. AvGas evaporates right away. Jet fuel is greasy and won't.

Agreed. Smell and color will tell as well.

I suspect the OP is concerned about a contaminated delivery, where some percentage of the 100LL tank is mixed with Jet A. I suspect specific gravity may be helpful in that situation.

 

[James331]

Just supervise the fueling of your plane, or better yet do it yourself.

 

[Brad Z]

Just supervise the fueling of your plane, or better yet do it yourself.

How about supervising the filling of the storage tank?

 

[PaulMillner]

Just supervise the fueling of your plane, or better yet do it yourself.

That doesn't help if there's jet in the avgas, like Chevron 1994...


Paul

 

[PaulMillner]

There are MUCH easier ways to detect jet fuel.

Easiest is to drop it on some white paper. AvGas evaporates right away. Jet fuel is greasy and won't.

I submit that watching the yellow bead in the fuel cup is easier than organizing the white paper drop test...


Had that exact issue preflighting in the rain today...


Paul

 

[Graueradler]

Before a fuel delivery starts into our storage tank from the delivery truck, it has to be within +/- 1 of the specific gravity of the batch analysis from the refinery whether it is 100LL or Jet A. The devices that we use for measuring would not be very practical to carry for pre-flight They can be obtained from suppliers like Crown Products of Tulsa or The Southern Co. in Little Rock/ Ft. Smith.

 

[stevenclin]

A long time ago - maybe 10-15 years - Sporty's used to sell a fuel tester cup that had a small yellow ball in it. The ball had the appropriate density to sink in avgas but float in Jet A (and water). So, if the ball was floating or partially floating, you knew you might have some contaminant in your tanks, but if it sunk, you knew you likely had avgas.

I was looking to buy such a fuel tester and discovered that they don't seem to sell this type of thing anymore. Neither does Aircraft Spruce or Sky Geek or my other usual sources.

Has anyone seen this type of tester in the recent past and/or know of a source?

Thanks!
Steve

While I appreciate all the helpful preflighting tips I guess the lack of response to my question means that this type of fuel cup / tester is no longer being made.

Not that it matters, but the nice thing about the yellow ball tester is that it tests the fuel automatically every single time you sample -- you're already sampling to check for water and other contaminants, so having the ball in the tester is an "instant" check done every single time you sample.

I know about the white paper trick but do you really do that every time you sample the fuel? I don't, and can't remember ever seeing anyone do it. (I also don't know what percentage of jet fuel is required to "fail" that test.) Yes, I use self serve and/or supervise the fueling when I can but that doesn't happen 100% of the time, and it doesn't catch when the fuel truck or tank has jet mixed with the avgas by mistake.

I also know about the GATS jar whose screen, once the avgas evaporates, can indicate jet fuel contamination. But, these other methods, practically speaking, are only useful when you already suspect a misfueling event. I don't think many people use the paper trick or wait for the GATS screen to dry out every time they sample.

Just to be clear - I have one of these specific gravity testers now, and I remember I bought it at Sporty's for like $10-$20; it wasn't some exotic piece of equipment or anything. It's just showing its age so I was hoping I could get a replacement, but perhaps they are no longer manufactured - bummer!

 

[Johann]

While I appreciate all the helpful preflighting tips

You got it easy, you should see what happened to the last guy that came here asking for an item he had before and couldn't find for sell anymore

(For those that don't remember, the item in question started with Metal and ended with Landing Calculator)

 

[MauleSkinner]

I know about the white paper trick but do you really do that every time you sample the fuel? I don't, and can't remember ever seeing anyone do it. (I also don't know what percentage of jet fuel is required to "fail" that test..)

What percentage of jet fuel is required for your floating ball to fail the test?

I also know about the GATS jar whose screen, once the avgas evaporates, can indicate jet fuel contamination. But, these other methods, practically speaking, are only useful when you already suspect a misfueling event. I don't think many people use the paper trick or wait for the GATS screen to dry out every time they sample.

It's pretty easy to set a GATS jar down next to the airplane and pick it up to check when you come back around on your preflight. That's what I always did when I used one.

 

[Henning]

There are MUCH easier ways to detect jet fuel.

Easiest is to drop it on some white paper. AvGas evaporates right away. Jet fuel is greasy and won't.

I don't think there is any easier way than to have a hydrometer built into your sampler.

 

[Henning]

While I appreciate all the helpful preflighting tips I guess the lack of response to my question means that this type of fuel cup / tester is no longer being made.

Not that it matters, but the nice thing about the yellow ball tester is that it tests the fuel automatically every single time you sample -- you're already sampling to check for water and other contaminants, so having the ball in the tester is an "instant" check done every single time you sample.

I know about the white paper trick but do you really do that every time you sample the fuel? I don't, and can't remember ever seeing anyone do it. (I also don't know what percentage of jet fuel is required to "fail" that test.) Yes, I use self serve and/or supervise the fueling when I can but that doesn't happen 100% of the time, and it doesn't catch when the fuel truck or tank has jet mixed with the avgas by mistake.

I also know about the GATS jar whose screen, once the avgas evaporates, can indicate jet fuel contamination. But, these other methods, practically speaking, are only useful when you already suspect a misfueling event. I don't think many people use the paper trick or wait for the GATS screen to dry out every time they sample.

Just to be clear - I have one of these specific gravity testers now, and I remember I bought it at Sporty's for like $10-$20; it wasn't some exotic piece of equipment or anything. It's just showing its age so I was hoping I could get a replacement, but perhaps they are no longer manufactured - bummer!

Which is sad since it's such a simple low cost item that could be added to every sampling device.

 

[overdrive148]

Obligatory:

http://www.pilotsofamerica.com/forum/showthread.php?t=74702

 

[James331]

That doesn't help if there's jet in the avgas, like Chevron 1994...


Paul

Sigh

Just sump as normal. I'm not super concerned about someone filling the 100ll tank with Jet A. There are a million other things that are way more likey to kill you, and the chances of that occurring are slim to say the least.

 

[Henning]

Sigh

Just sump as normal. I'm not super concerned about someone filling the 100ll tank with Jet A. There are a million other things that are way more likey to kill you, and the chances of that occurring are slim to say the least.

Except that it's been the cause of 3 fatal accidents just this year IIRC. While the odds of all aviation accidents occurring is small, mis-fueling is not really at the minuscule end of scale. Figure if there is 1 fatal per week, those 3 fatals would represent over 5%. That would be a significant share.

 

[James331]

Except that it's been the cause of 3 fatal accidents just this year IIRC. While the odds of all aviation accidents occurring is small, mis-fueling is not really at the minuscule end of scale. Figure if there is 1 fatal per week, those 3 fatals would represent over 5%. That would be a significant share.

I think we are talking two different things here.

I'm talking about fuel contamination from the source, NOT someone sticking a JET A nozzle into a 100LL plane.

 

[Henning]

I think we are talking two different things here.

I'm talking about fuel contamination from the source, NOT someone sticking a JET A nozzle into a 100LL plane.

It doesn't matter why it happened, if you measure for it every time you sump with no additional effort or experimentation just by adding a couple of BBs of a known density to a tester for an extra 10¢ is a no brainer. I along with the OP question why this is no longer available.

 

[James331]

It doesn't matter why it happened, if you measure for it every time you sump with no additional effort or experimentation just by adding a couple of BBs of a known density to a tester for an extra 10¢ is a no brainer. I along with the OP question why this is no longer available.

I agree with it being odd not to have that whiz bang feature. Still think just supervising fueling or self fueling and sumping suffices.

Here ya go

http://www.labdepotinc.com/Product_Details~id~482~pid~61278.aspx?gclid=CLXot-qXssICFS0Q7Aod5zcA9A

25 bucks.

100LL is .68-.74 at 60f

JET A is .8

Water is ofcourse 1.

 

[Henning]

I agree with it being odd not to have that whiz bang feature. Still think just supervising fueling or self fueling and sumping suffices.

Here ya go

http://www.labdepotinc.com/Product_Details~id~482~pid~61278.aspx?gclid=CLXot-qXssICFS0Q7Aod5zcA9A

25 bucks.

100LL is .68-.74 at 60f

JET A is .8

Water is ofcourse 1.

That's what I use when I'm buying fuel by the ton. I think having a simple SG-BB hydrometer like simple anti freeze and battery testers is a perfectly accurate method that requires no additional effort, or delicate equipment to perform.

 

[Norman]

Sigh

I'm not super concerned about someone filling the 100ll tank with Jet A.

Stuff happens. A few years back, a local gas station got a drop. Unfortunately it was diesel and was put in the regular gas tank. Cost the oil company a few bucks to repair all the engines they killed.

 

[Marky_24]

"Finally, a good fuel tester is cheap insurance, and one I often recommend is the ClearSight Fuel Tester ("Pilot Products," February 1990 Pilot). Available in both tube and cup styles, the ClearSight has a ball inside calibrated to distinguish between the specific gravity of avgas and water or jet fuel. If there is water or jet fuel in your sample, the ball floats on top of it but beneath the avgas. It is particularly handy at night. I've been using one for a year, and it has never failed to discover the gobbet of water that is always present in the left fuel strainer of an Aztec I know. $14.95, plus shipping, from For-Mar Aviation Specialties, 313 George Avenue, Amery, Wisconsin 54001; telephone 715/268-2247."

They existed in 1990, i guess you could call the number and see what happens.

 

[Henning]

"Finally, a good fuel tester is cheap insurance, and one I often recommend is the ClearSight Fuel Tester ("Pilot Products," February 1990 Pilot). Available in both tube and cup styles, the ClearSight has a ball inside calibrated to distinguish between the specific gravity of avgas and water or jet fuel. If there is water or jet fuel in your sample, the ball floats on top of it but beneath the avgas. It is particularly handy at night. I've been using one for a year, and it has never failed to discover the gobbet of water that is always present in the left fuel strainer of an Aztec I know. $14.95, plus shipping, from For-Mar Aviation Specialties, 313 George Avenue, Amery, Wisconsin 54001; telephone 715/268-2247."

They existed in 1990, i guess you could call the number and see what happens.

Hah, no wonder they failed, $15 is way too expensive for something that may never find a problem and save your life. It's just not worth the extra $10, and besides, the plane already has a sumping tool and I can buy 3 gallons of gas with that money. Pilots are so funny they would kill me if they weren't busy killing themselves. I'll bet the majority of aircraft accidents happen because someone was trying to save <$15. (Think not getting fuel because the fuel was 20¢ a gallon cheaper at the next stop, then running out no the way)

Also the company failed to advertise. Had I known they existed, I would have one.

 

[Morgan3820]

A long time ago - maybe 10-15 years - Sporty's used to sell a fuel tester cup that had a small yellow ball in it. The ball had the appropriate density to sink in avgas but float in Jet A (and water). So, if the ball was floating or partially floating, you knew you might have some contaminant in your tanks, but if it sunk, you knew you likely had avgas.

I was looking to buy such a fuel tester and discovered that they don't seem to sell this type of thing anymore. Neither does Aircraft Spruce or Sky Geek or my other usual sources.

Has anyone seen this type of tester in the recent past and/or know of a source?

Thanks!
Steve

I have a couple ass described. I always wondered what that yellow ball was for. Thanks. I usually just smell the fuel.

 

[petrolero]

There are MUCH easier ways to detect jet fuel.

Easiest is to drop it on some white paper. AvGas evaporates right away. Jet fuel is greasy and won't.

This is the easiest and most reliable test I have seen. Specific gravity balls are not accurate enough to detect minute amounts of oil (Jet A) in avgas. But the paper test does detect it.

Agreed. Smell and color will tell as well.

I suspect the OP is concerned about a contaminated delivery, where some percentage of the 100LL tank is mixed with Jet A. I suspect specific gravity may be helpful in that situation.

Not necessarily. A little jet fuel won't change the SG much and, as shown in the excellent thread below, it doesn't change the color much even at 50% Jet A. Shocking. The smell test wasn't reliable either at lower concentrations of Jet A.

Nor is there necessarily a meniscus or boundary layer between the two fuels - they are both petroleum products and are miscible.

I submit that watching the yellow bead in the fuel cup is easier than organizing the white paper drop test...


Had that exact issue preflighting in the rain today...


Paul

Easier perhaps, but less accurate.

Obligatory:

http://www.pilotsofamerica.com/forum/showthread.php?t=74702

I also recommend this this fantastic thread ^^^