Dining hall workers yesterday checked students' bursar's cards with special imprinting machines as part of a University "spot audit" aimed at discovering the number of students who are misusing the cards to get free meals.

Joe B. Wyatt, vice president for administration, said yesterday he ordered the audit after Frank J. Weissbecker, director of Food Services, expressed concern that many students without board contracts might be using lost or stolen cards to fool the dining hall checkers.

Wyatt said the use of the imprinting machines, which resemble those used to register credit-card purchases, would allow the University to keep an exact record of the number of students who had used invalid cards to gain admission to dining halls.

One-Day Stand

The University will not repeat the procedure unless administrators think they have not traced all the students who are misusing cards, Wyatt said.

"If the problem is widespread we cannot rule out the use of such methods as a computerized checking system," he added.

Weissbecker said he was worried that the administration did not know how many students might be using improper cards to get past the dining hall checkers.

Concern about misuse of bursar's cards arose last fall after the University mistakenly issued over 300 cards good for board to Dudley House students who did not have board contracts. Over 250 students reported receiving the wrong cards but University officials never determined the exact number that were issued.

Food Services officials said yesterday the elimination of student pictures from bursar's cards this year has made them more difficult to trace than in the past.

R. Jerrold Gibson '51, director of the Office of Fiscal Services who last year proposed that dining hall checkers use computerized card-readers to prevent illegal use of bursar's cards, said yesterday he had not heard of the decision to hold the audit.

Wyatt said he does not know when the University will receive the results of the audit.

Most of the freshmen in line for dinner outside the Union last night took the surprise audit in stride, although a few expressed bewilderment at the new machine the checkers were using to examine their cards.

"For a moment, I was tempted to pull out my Master Charge," Constance C. Russell '80 said yesterday.

Other students expressed annoyment at the inconvenience the audit caused.