Testing at Lincolnshire Showground is set to be ramped up to around 1,000 per day capacity by the end of the week.
Public health bosses in the county said they were confident that the facility would be able to carry out the target number of tests as the site was “working well”.
It was announced last week that the Showground site, which is run by Boots and Serco, would replace three sites in Lincoln and Boston.
Tests are still appointment only and targeted at key workers and frontline NHS staff.
Professor Derek Ward, director of public health at Lincolnshire County Council, said the site had 400 tests planned for today (April 28).
The site was opened on Sunday and carried out 155 tests in its first day.
Professor Ward said he was confident of getting the facility up to capacity by the end of the week.
“From all of the indications we are getting, it [the site] seems to be working quite well,” he said.
Officials have started to open up mobile testing sites with the first at Princess Anne Sports Centre in Boston and another expected to start up in Skegness.
It comes as part of government plan to ramp up testing for thousands of key workers across the country.
Local health bosses have set a target for 1,000 tests per day across the county.
Officials said that testing was also been ramped up in care homes where both staff and residents can now be tested.
Along with testing, the county will need an increase in tracing teams to confirm positive cases.
Among those to be part of the tracing teams will be civil servants and council staff, such as environmental health officers.
Up to 150 tracers will need to be trained in Lincolnshire in order to track down individual cases.