The phrase "high accuracy" means being very precise or correct. It implies that something is extremely reliable and can be trusted to give accurate results or information. Full definition
By being able to measure electron density with high accuracy in atmospheric pressure low - temperature plasma, it is no longer necessary to rely solely upon experience and trial and error. (sciencedaily.com)
In one study, doctors who reviewed scans while walking on a treadmill had a 10 % higher accuracy rate of diagnosing lesions than doctors who were sitting. (rebeldesk.com)
We can date the chemicals in the earth with very high accuracy. (religion.blogs.cnn.com)