Three-hundred automated devices to test for COVID-19 were put into service on Wednesday in Xinxiang, Henan province. Residents can now take nucleic acid tests by themselves, the city's epidemic control and prevention headquarters said.

The device looks like a laptop computer. Beside it are rubbing alcohol, cotton swabs and a nucleic acid test tube. They have been placed in shopping malls, supermarkets and schools.

After scanning their code on the device, residents sterilize their hands and then collect a saliva sample from their mouth using a swab. The device gives a result or requires repeating the test procedure.

"The devices were developed to save residents' time lining up for tests. They also reduce infection risks," said Cheng Dong, the leader of the city's nucleic acid test team at the headquarters.

The whole test process takes 15 to 30 seconds for residents who are familiar with the device, Cheng said.

"We also test the devices and upgrading them to make them work more efficiently," he said.