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

**elwray** · 06-18-2009 02:41 PM

Originally Posted by sti27cbrd

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.

NJ's environmental regulations are MUCH stricter than PA's. Plus, I'd assume with the population density here, more people=more cars=more gas stations=more leaks? Makes sense to me at least

**elwray** · 06-18-2009 02:47 PM

Originally Posted by 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).

I would imagine that the volume scales linearly regardless of total volume pumped. Therefore it could be off by a percent. As far as the margin of error of 5 cubic inches out of 5 total gallons, that would be 0.4%. Not too shabby actually.

***mycologist*** · 06-18-2009 02:57 PM

Originally Posted by elwray

I would imagine that the volume scales linearly regardless of total volume pumped. Therefore it could be off by a percent. As far as the margin of error of 5 cubic inches out of 5 total gallons, that would be 0.4%. Not too shabby actually.

Why would a linear scale be needed if only the total for a 0-5 gallon pull is used to test it and it is a digital interface?

**elwray** · 06-18-2009 03:02 PM

Originally Posted by mycologist

Why would a linear scale be needed if only the total for a 0-5 gallon pull is used to test it and it is a digital interface?

Maybe I misunderstood your first question, but I don't see what you're getting at here...

What you're saying, is that the miscalibration isn't necessarily an issue with the pump, but that the computer could be rigged to count up faster at 5+ gallons than the actual amount being dispensed?

**Sasquatch** · 06-18-2009 03:03 PM

Originally Posted by 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).

Ah, got it.

As I just found out the 5 gallon test is the standard in PA.

***mycologist*** · 06-18-2009 03:09 PM

Originally Posted by elwray

Maybe I misunderstood your first question, but I don't see what you're getting at here...

What you're saying, is that the miscalibration isn't necessarily an issue with the pump, but that the computer could be rigged to count up faster at 5+ gallons than the actual amount being dispensed?

Ding, yes. It only has to be accurate at one single point. It isn't even testing the relationship across 0-5 (i.e at 3 you could hypothetically get 2.5).

**elwray** · 06-18-2009 03:11 PM

Well then, in that case I suppose if you're running a gas station in PA, all you have to do is make sure you can pass the 5 gallon test. After that you can inflate your pump volumes as much as you think you can get away with!

**elwray** · 07-04-2009 07:12 PM

In case anyone's interested..

A fuel dispenser salesman from Dresser Wayne (one of the major manufacturers in the business) came in to our office last week to talk to us about their products... and touched on the calibration testing.

What I got from it, is that there isn't as much electronics involved in the pump/dispenser counter. There's a physical unit in there that counts the gallons pumped, and that relays the information to the mechanical or digital display on the front. So at least the products that we were shown, there isn't any way to "program" anything that would change after 5 gallons.