Are you getting all the gasoline you paid for in PA?

[Sasquatch]

Surely you have noticed the decals on gas pumps stating when they were last tested for accuracy ...

I happened to stop by a gas station today while the pumps were being tested. I asked the guy doing the testing a few questions and he got rather chatty - he really likes his job. For the most part gas pumps are usually pretty accurate - he rarely sees pumps off by significant amounts.

How its done:

They pump 5 gallons (640 ounces) into a special container that has mechanical apparatus with a glass tube and a scale next to it calibrated in cubic inches. The threshold for a pass or failed test is 6 cubic inches low (6 cubic inches = 3.324 ounces).

So for every gallon (128 ounces) you pump, you should get no less than 127.3352 ounces (if I did the math correctly).

The guy also tests liquid propane and heating oil trucks. I asked about their accuracy. He said "no comment" with a "look" to convey he has seen those off by a fair amount.

[EJ257]

There was a CAL here in NY (or at least it was brought up) about people getting screwed by pumps a while ago

[Speedette]

LOL definitely filing this under "Things I didn't know I wanted to know, but I'm glad I know now".

Thanks Bill! You're very inquisitive.

[Sasquatch]

LOL definitely filing this under "Things I didn't know I wanted to know, but I'm glad I know now".

Thanks Bill! You're very inquisitive.

I was mildly curious - the test guy was very chatty.

[sti27cbrd]

i wish they'd run surprise tests on proper water content in gas...

[wrx wagone]

I was mildly curious - the test guy was very chatty.

He was hitting on you.

[elwray]

Surely you have noticed the decals on gas pumps stating when they were last tested for accuracy ...

I happened to stop by a gas station today while the pumps were being tested. I asked the guy doing the testing a few questions and he got rather chatty - he really likes his job. For the most part gas pumps are usually pretty accurate - he rarely sees pumps off by significant amounts.

How its done:

They pump 5 gallons (640 ounces) into a special container that has mechanical apparatus with a glass tube and a scale next to it calibrated in cubic inches. The threshold for a pass or failed test is 6 cubic inches low (6 cubic inches = 3.324 ounces).

So for every gallon (128 ounces) you pump, you should get no less than 127.3352 ounces (if I did the math correctly).

The guy also tests liquid propane and heating oil trucks. I asked about their accuracy. He said "no comment" with a "look" to convey he has seen those off by a fair amount.

Does this container have some kind of calibration for temperature, or is that part of the 6ci wiggle room they have?

i wish they'd run surprise tests on proper water content in gas...

They're strict about that in NJ; I don't know much about PA regulations. Every UST system here must have probes measuring inches of water in the tank (can be used to determine gallons). NJDEP conducts inspections periodically of these systems, as well as checks the monthly printouts/records of the system.

However, the goal of all that isn't to prevent pumping water contaminated gas into your car, it's to prevent groundwater contamination -- if water's getting into the UST, then chances are there's a hole/crack/leak and product is getting out.

[Trainrex]

He was hitting on you.

Can you blame him?

[mycologist]

Contemplates how simple it would be for a computerized pump display to be accurate at only 5 gallons.

[Sasquatch]

He was hitting on you.

Maybe he was bored ... maybe no one ever asked what he was doing? Maybe the Neanderthal look gets him all worked up.

Does this container have some kind of calibration for temperature, or is that part of the 6ci wiggle room they have?

With all the info I got temperature was never mentioned. Might have been something built into the mechanical works - it gets calibrated twice a year

Contemplates how simple it would be for a computerized pump display to be accurate at only 5 gallons.

[Sasquatch]

What can't you find on the Internet...

I think this was the exact device used. Not as mechanical as he let on.

Seraphin Test Measures - - Test Measures

[elwray]

Maybe he was bored ... maybe no one ever asked what he was doing? Maybe the Neanderthal look gets him all worked up.

With all the info I got temperature was never mentioned. Might have been something built into the mechanical works - it gets calibrated twice a year

I doubt anyone ever asks what he's doing. I love when people ask me what I'm doing (which coincidentally is usually at gas stations as well)!

Whenever I'm out with a drill rig putting in monitoring wells or taking soil cores, someone ALWAYS says one of the following:
"Drillin' for oil???"
"Find any gold???"

Or my personal favorite:

"Lookin' for Jimmy Hoffa down there!?"

As far as temp goes, unless they just got a new delivery, the temperature in the ground should be fairly consistent. Whenever I look at the printouts from the monitoring systems, they generally have a temp ~55 if I recall correctly.

[Hold_Fast]

i wish they'd run surprise tests on proper water content in gas...

A gas station down the street from me is well known for just that. I stopped by my local garage one day and the one mechanic had a 5 gallon bucket filled with their "gas". The first 4 inches were water.

[sti27cbrd]

They're strict about that in NJ; I don't know much about PA regulations. Every UST system here must have probes measuring inches of water in the tank (can be used to determine gallons). NJDEP conducts inspections periodically of these systems, as well as checks the monthly printouts/records of the system.

However, the goal of all that isn't to prevent pumping water contaminated gas into your car, it's to prevent groundwater contamination -- if water's getting into the UST, then chances are there's a hole/crack/leak and product is getting out.

that is particularly amusing considering how many more times i have heard of this being a problem in NJ than other places around here. it only takes a few stations to make a problem more well-known, but i have heard of so many of them from jersey.

[mycologist]

Simply saying if they only test 5 gallons to be 5 gallons, how do they know that that relationship pertains to the range of volumes being dispensed. I.e. who is to say that with a digital interface you might not be getting 8 gallons when 9 is pumped but 5 gallons when 5 is pumped. Seems like this would be easy to test by dispensing random amounts prior to measuring out the 5 gallons, not starting at 0 each time. My impression was they do not do that though. In OR they tested 5 gallons and 10 gallons (still sub-optimal IMO).