Rosalyn Carter saw today what life and disease are like in a squalid camp of Cambodian refugees and came away calling it "overwhelming, emotionally overwhelming."

President Carter's wife spoon-fed rice to a malnourished woman in a primitive hospital ward, met with a blinded man and managed to elicit a few smiles from a tentful of Cambodian children whose parents are dead or missing.

Thai soldiers armed with M16 rifles guarded Mrs. Carter and her entourage closely during their two hours in the newly opened camp at Sa Kaew, about 40 miles from Cambodian border. The camp contains about 32,000 Cambodians, the most recent arrivals of more than 200,000 who have fled since the Vietnam-backed takeover in Phnom Penh last January and the subsequent famine. Most of those Mrs. Carter saw are loyal to the ousted Khmer Rouge government of Pol Pot, which -- like the current rulers in Phom Penh -- was communist.

After Mrs. Carter's first-hand look at the refugee's despair, she told reporters: "It was very difficult for me to go through the camp and see the people and the disease and the poverty . . . I want to go home and do all we possibly can to help . . . It's like nothing I have ever seen."

Thai troops, meanwhile, were reported to have occupied and sealed off the refugee camp known as 511, about 45 miles away. Following a clash with right-wing Khmer Serei guerrillas there, Thai troops fired mortars on Camp 511 yesterday shortly before Mrs. Carter arrived in Bangkok.

A Thai military spokesman said two Thai soldiers had been killed in the exchange. But he had no figures on Cambodian casualties. Journalists present at the time said scores of civilians died. Mrs. Carter, surrounded by Thai Army officers, foreign relief workers and Secret Service agents, and with perhaps 150 journalists covering every step of her tour, had little chance for intimate exchanges with people she met.

Conversations with refugees indicated most did not know who their visitor was and seemed unaware of the political ironies of receiving the first lady of a country that fought and financed a five-year war against the Khmer Rouge. The Khmer Rouge captured Phnom Penh in 1975, then were driven out by Vietnamese forces in January.

Refugee men, dressed in black pants and shirts and with traditional checkered scarves wrapped around their heads, squatted in silence at the camp gate, seemingly oblivious of a large American flag unfurled to welcome Mrs. Carter.

Young men, some apparently Khmer Rouge cadre, sported yellow armbands and policed other refugees who gathered along the camp's dusty thoroughfares. When Mrs. Carter's entourage passed by, faces looked on with no visible reaction.

"They told us someone important from America was coming, but that was all," said a man in his twentities after Mrs. Carter passed his tiny hut. wMost other people interviewed denied any knowledged of the nationality, of the people causing the commotion. "Our leaders ordered us to come out and watch," said a 40-year old man with a shrapnel scar on his cheek.

The only sign of popular enthusiasm for Mrs. Carter at this camp came out as she was getting into her car to leave. A group of Chinese-Cambodians -- they form an unpopular minority in the Sa Kaew camp and despise the Khmer Rouge -- began to applaud. Most of Sa Kaew's 900 Chinese want to resettle overseas.

Mrs. Carter spent most of her tour inside hospital tents. Disease is still rampant and over 400 people have died at Sae Kaew since the camp opened Oct. 24. In one ward, Mrs. Carter bent close to a small girl and got a beaming smile. The girl coughed; Mrs. Carter put her hand on her shoulder to steady the girl. "Have you been able to eat your food?" she asked another patient through an interpreter.

From Sa Kaew, Mrs. Carter's party flew to the town of Ubon in northeastern Thailand for a quick walking tour of a camp of 36,000 refugees from Laos. Compared to Sa Kaew, the Ubon camp is a model community. It was built on the site of a former U.S. Air Force bomb dump and has paved streets, neat bamboo and thatch houses, generally healthy-looking people. Its appearance was helped further by platoons of soldiers assigned to spruce it up in recent days.

Unlike Sa Kaew, in which a shadow Khmer Rouge administration operates, Ubon camp is peopled with firm anticommunists. Most have been accorded official status as refugees -- Sa Kaew's peoples are ranked as "illegal persons" -- and want to go abroad.

Small children showed enthusiasm for their visitor, with groups running after her shouting endearments. One small girl presented her with a ring.

Talks with refugees in the streets indicated many knew who Mrs. Carter was and recognized that her visit might help in emigrating.

Questions about Mrs. Carter quickly led some of the refugees interviewed to make good-natured complaints about the U.S. resettlement program. "Why does America take so few Laotians?" a teen-age boy asked. The U.S. takes only former employees of the U.S. aid mission. It doesn't take ordinary people," another said.

From Ubon, Mrs. Carter's party flew to the mountain palace in Sakon Nakhorn Province for an audience with King Bhumibol Adulyadej and Queen Sirikit. The royal couple entertained Mrs. Carter with tea and Mrs. Carter presented Queen Sirikit with a check for $100,000 for the Thai Red Cross' relief efforts with refugees.

On Saturday Mrs. Carter is to meet with Thai Prime Minister Kriangsak Chamanan and representatives of relief agencies. She will also see seven U.S. House members, all women, led by Rep. Elizabeth Holtzman (D-N.Y.), who have received permission to visit Phnom Penh on Monday to discuss food aid to Cambodia.