Mrs Devers' imperial weighing scales were seized from her market stall
An east London market trader found guilty of breaking metric laws has been given a conditional discharge.
Janet Devers, 64, used imperial weighing scales, without an official stamp, on her fruit and veg stall at Ridley Road Market in Dalston.
She was convicted of eight charges under the Weights and Measures Act at Thames Magistrates Court.
Through choice, Mrs Devers will stand trial at a crown court in January in relation to four more similar charges.
Officers from Hackney Council, which brought the prosecution, seized Mrs Devers' scales saying she failed to follow European Union (EU) rules.
The chairman of the magistrates court, Dr Patrick Davies, told her: "You said you were doing this in the interests of your customers although you ought to have known you were breaking the law."
Mrs Devers said she had had great support from customers at her vegetable store.
"My customers say they cannot believe it. They cannot believe that they have prosecuted me even when every place in London, every market still does the same as me, but I have been prosecuted for it.
"I was victimised by Hackney Council. Colin Hunt was my brother, one of the Metric Martyrs. They knew I was his sister and they made me an example."
Mrs Devers was convicted of selling scotch bonnets, pak choi and okra in bowls on her stall in September last year. She was cleared of one charge of selling sweetcorn without a unit price.
Neil Herron, of the Metric Martyrs campaign, said: "Right across the country there is only one council in eight years that has decided this is a worthy way to spend public money."
A spokeswoman for Hackney Council said: "We are satisfied with the outcome of this case but regret that legal action was required.
"It would have been much better if Mrs Devers had complied with the law 18 months ago."
Last September, European Union commissioners ruled that Britain can carry on using imperial measurements such as pints, pounds and miles.
Europe's Industry Commissioner Gunter Verheugen said at the time: "There is not now and never will be any requirement to drop imperial measurements."