Hi all Having read peoples concerns over MIRO weights does anyone know the accuracy of weighbridges
Weighbridges
- Thread starter James_374408700
- Start date
James, they are regulated l suppose by the weights and mesure's which have an agreed tolerence, and yes not 100% but mayebe 99.9%.
Having said that some l been to had top soil from the previous load, so it depends on what you are looking for in respect of accuracy, l don't think a couple of kiloes will make that much difference.
All l am looking for is that l am within the the law what my car can tow and the caravan can safely be loaded to within an acceptable tolerence, not down to a gram or to.
Nigel
Nigel H
Having said that some l been to had top soil from the previous load, so it depends on what you are looking for in respect of accuracy, l don't think a couple of kiloes will make that much difference.
All l am looking for is that l am within the the law what my car can tow and the caravan can safely be loaded to within an acceptable tolerence, not down to a gram or to.
Nigel
Nigel H
Trading standards do not require a specific accuracy of a weighbridge, but the weighbridge operator must know the details applicable to his particular weighbridge and be able to provide calibration data on demand. The 5% tolerance allowed by the police is to take care of any errors of the weighbridge.
On weighbridges I've used, the reading increases in steps of 20kg so there's a tolerance of +/-10kg even if the weighbridge was otherwise 100% accurate.
Lutz is basically right, a weigh bridge weighs to +/- 5% and it is regularly calibrated.
Most digital bridges weigh to +/- 5Kgs on the readout.
Believe me your local grain merchant would not want to buy or sell grain at a loss to him. You know how thrifty farmers are!
The police and VOSA are quite understanding and generally only prosecute those who are blatently over weight. They prefer to opt for education, especially if you display genuine innocense.
We got stopped a few years ago for not having a tachograph fitted to our 3500Kg truck while towing a 2000Kg trailer. We thought, here comes a thousand pound fine. But how wrong we were. We arranged for a tackograph to be fitted within 48 hours and when the notice of prosecution arrived we wrote back stating that we were totally unaware that we needed a tacho until the officer had advised us, and then within 48Hrs of being told that, we had got a tacho fitted.
All we got was a letter of formal warning and a note saying no further action would be taken.
Now that was lucky I guess, or was it someone taking advice and acting swiftly and politely to rectify the error.
Which ever you choose as the reason for the let off, it does prove that not all cops are bad boys.
Steve L.
Most digital bridges weigh to +/- 5Kgs on the readout.
Believe me your local grain merchant would not want to buy or sell grain at a loss to him. You know how thrifty farmers are!
The police and VOSA are quite understanding and generally only prosecute those who are blatently over weight. They prefer to opt for education, especially if you display genuine innocense.
We got stopped a few years ago for not having a tachograph fitted to our 3500Kg truck while towing a 2000Kg trailer. We thought, here comes a thousand pound fine. But how wrong we were. We arranged for a tackograph to be fitted within 48 hours and when the notice of prosecution arrived we wrote back stating that we were totally unaware that we needed a tacho until the officer had advised us, and then within 48Hrs of being told that, we had got a tacho fitted.
All we got was a letter of formal warning and a note saying no further action would be taken.
Now that was lucky I guess, or was it someone taking advice and acting swiftly and politely to rectify the error.
Which ever you choose as the reason for the let off, it does prove that not all cops are bad boys.
Steve L.
My point in posting this topic is that owners appear to be taking the reading at the weighbridge as gospel. If there is a +/- 5% tolerance (inaccuracy) this would mean that a van weighing 1350kg COULD display a weight of 1417kg which would frighten some owners to death. I have read other postings of people doing exactly this and then trying to readjust loadings to compensate when in effect there MAY be nothing wrong!
5% is reasonable given the gross weights involved,you've got to have something to work from and take as Gospel. Every trip you make with the van will have a different weight anyway. If it bothers you that much then go to a few different weighbridges and then take the average weight.
missed a bit... There's also nothing stopping you weighing your car on the same bridge as well which will also give you an accurate-ish percentage towing ratio which is probably more important for peace of mind.
Steve - quite a lot of organisations didn't notice the Tachometer regulation which doesn't need one for a goods vehicle up to 3500kg but does require a tachometer if a trailer is being used commercially and the outfit is over 3500kg - when enforcement started, it was often with a warning rather than a prosecution first time.
As this is a caravan forum, tachometers aren't needed to tow caravans for private use.
As this is a caravan forum, tachometers aren't needed to tow caravans for private use.
The lorry weigh bridges we had that weighed the scrap metal lorries, would be inaccurate for weighing a caravan.
Most weighs use 4 load cells mounted on the corners, the load cell outputs are connected in a wheatstone bridge arrangment, then pass through the electronics via zero and span adjustments, out to the weigh display.
The thing is on a bridge designed to weigh say 40 ton for a figure.
The weigh is just not accurate at the bottom end.
A regular calibration would consist of a number of calibrated weights sufficent to adjust the span, after first checking the tare producers zero.
I have never used a weigh bridge to weigh my van, but if i did, i would be looking for one with the smallest span.
We had a couple of weigh fitters that did our calibrations, required for QA.
However we were expected to carry out repairs to the load cell wiring, and electronics, to help with this a test weight was available.
For a 20T span, the test weight was around 10T, the slabs the crane lifted would be 10/15T.
For this test weight the reading had to be +/- 10kg, the displays did show in increments of 10kg, even on the 130T crane weighs.
And yes there is a tolorance.
Most weighs use 4 load cells mounted on the corners, the load cell outputs are connected in a wheatstone bridge arrangment, then pass through the electronics via zero and span adjustments, out to the weigh display.
The thing is on a bridge designed to weigh say 40 ton for a figure.
The weigh is just not accurate at the bottom end.
A regular calibration would consist of a number of calibrated weights sufficent to adjust the span, after first checking the tare producers zero.
I have never used a weigh bridge to weigh my van, but if i did, i would be looking for one with the smallest span.
We had a couple of weigh fitters that did our calibrations, required for QA.
However we were expected to carry out repairs to the load cell wiring, and electronics, to help with this a test weight was available.
For a 20T span, the test weight was around 10T, the slabs the crane lifted would be 10/15T.
For this test weight the reading had to be +/- 10kg, the displays did show in increments of 10kg, even on the 130T crane weighs.
And yes there is a tolorance.
Hi Roger.
The point I was trying to illustrate is that not all enforcers are hostile. They do understand the difference between accidental or couldn't give a dam.
A lot of people start to look at caravanning and if we appear to make it look too technical or they belive they are going to be hounded, then they just give up.
The enforcers themselves would often welcome enquiries and will be only too pleased to give advice free of charge.
I can recall that our local vehicle testing station at Hereford held an open morning so that people could go along and ask questions or have their trailers looked at.
Steve L.
The point I was trying to illustrate is that not all enforcers are hostile. They do understand the difference between accidental or couldn't give a dam.
A lot of people start to look at caravanning and if we appear to make it look too technical or they belive they are going to be hounded, then they just give up.
The enforcers themselves would often welcome enquiries and will be only too pleased to give advice free of charge.
I can recall that our local vehicle testing station at Hereford held an open morning so that people could go along and ask questions or have their trailers looked at.
Steve L.
if a weighbridge is inaccurate, where do the manufacturers weigh a caravan, and how accurate is the weight plate?
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