adjective /ˈækjərɪt/
In exact or careful conformity to truth, or to some standard of requirement, the result of care or pains; free from failure, error, or defect; exact; as, an accurate calculator; an accurate measure; accurate expression, knowledge, etc.
For more than 90% of the figures (mostly drawn during 1976-1990), either a scale, or the given magnification, will allow the user to derive accurate measurements, even when these are lacking in the diagnosis.
Wikipedia foundation.