Testing by MyBroadband revealed that petrol stations present clients with precisely the amount of gas — or extra — than what they pay for.
Following the latest petrol and diesel worth will increase, we determined to check the accuracy of gas pumps.
To take a look at the calibration accuracy of particular person pumps, MyBroadband bought one litre of petrol from completely different filling stations and saved it in a clear jerry can.
We ensured that the can was sealed throughout transportation to restrict evaporation and forestall spills.
The gas quantity was then measured utilizing a graduated cylinder with a ±2.5ml accuracy.
As many gas pumps solely measure two decimal locations, it will be honest to permit for ±10ml within the measured quantity, as that is the accuracy with which the gas was allotted.
All the samples we collected had been effectively inside this restrict, with the bottom measured quantity from an Engen storage — 995ml.
What stunned us had been the outliers on the excessive finish. There was one pattern from Sasol of 1,017ml and the one from BP at 1,085ml.
Because of this huge discrepancy, we re-tested the BP station by shopping for one other litre, and this time measured 1,020ml.
During the second pattern, we observed some gas dripping from the nozzle even earlier than the pump measurement began. There was some gas already within the hose, growing the amount we acquired.
However, it is not going to considerably have an effect on a bigger fill quantity, as it’s an absolute error of the amount left within the hose and never a pump calibration error.
Our checks confirmed that gas pumps are precisely calibrated, guaranteeing that you get your cash’s price.
The desk under reveals the measured quantity of all of the samples.
|Filling Station||Measured Fuel||Percentage Difference from 1l|
|BP (2nd take a look at)||1020 ml||2.0%|
|BP (1st take a look at)||1085 ml||8.5%|