An Alexandria Circuit Court judge yesterday sentenced a local businessman to 15 days in jail, the first time in the city that a merchant received a jail term for consumer fraud.

Judge Donald H. Kent found Arvin Bielin, owner of the Stereo World Audio and Tape Center, and electronics appliance store, guilty of violating a court order prohibiting him from advertising used items unless he clearly stated they were not news.

Bielin's jail term was delayed until the court probation officers can prepare a report on him. Final sentence is scheduled for Oct. 11.

Judge Kent said however, that the report would have to be quite "compelling" for him to change the sentence. Bielin refused to talk with reporters following his conviction.

Prosecutors said yesterday that they believed the Bielin case was the first time new provisions of the state's Uniform Deceptive Trade Practices Act had been applied to a consumer fraud case.

Last January the court had ordered Bielin not to advertise or sell reconditioned items unless he "clearly and unequivocably" stated that the merchandise was not new. He also was ordered to advertise products at reduced prices only if the items advertised were the same as the ones on sale. Bielin was convicted yesterday of violating both those court orders.

Yesterday's case grew out of newspaper advertisements in The Washington Post, The Washington Star, and the Penny Saver, a northern Virginia advertising publication. At the hearing, four customers testified that they had been unable to purchase turntables and CB radios that had been advertised.

Robert F. Johnstone told the court that when he tried to purchase a CB radio advertised for $19.95 he was told that the price referred only to reconditioned sets, for new ones.

The other witnesses, William Winter and his son, Dann, testified that when they attempted to purchase stereo turntables at a Washington's Birthday sale they were told that the order had not arrived and that they must pay in cash to get the sale price.

The Winters testified that they paid for the turntable in cash but that after several days of further delays they canceled the order. Bielin, they said, accepted the cancelation but charged a 10 per cent fee.

Bielin took the stand in his own defense and argued that the newspaper advertisements included a disclaimer inside a box stating that some items were reconditioned and that others were floor samples.

"I argued that that (the box) was sufficient notice the prospective purchaser that in fact the items were limited and that some were not new items," Bielin's attorney said.

In addition to sentencing Bielin to the 15-day jail term, Judge Kent also fined Bielin's firm, Arvin, Inc. $250 for fraud.

In handing down the sentences, Judge Kent said the Court was committed to "seeing that citizens are not defrauded" and that he had imposed a jail sentence "because harsher treatment than a fine is needed."